runtime(java): Improve the matching of contextual keywords

- Recognise a _record_ contextual keyword.
- Recognise _non-sealed_, _sealed_, and _permits_ contextual
  keywords.
- Admit _$_ to keyword characters.
- Group _abstract_, _final_, _default_, _(non-)sealed_
  (apart from _(non-)sealed_, the incompossibility of these
  modifiers calls for attention).
- Remove another _synchronized_ keyword redefinition.

I have also replaced a function with an expression.  Before
patch 8.1.0515, it should have been declared :function! to
work with repeatable script sourcing; there is less to worry
about with an expression.

References:
https://openjdk.org/jeps/395 (Records)
https://openjdk.org/jeps/409 (Sealed Classes)
https://docs.oracle.com/javase/specs/jls/se21/html/jls-3.html#jls-3.8

closes: #14403

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

5 files changed, 128 insertions, 0 deletions

diff --git a/runtime/syntax/testdir/dumps/java_contextual_keywords_00.dump b/runtime/syntax/testdir/dumps/java_contextual_keywords_00.dump
new file mode 100644
index 0000000000..fdd8173e5e
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_contextual_keywords_00.dump
@@ -0,0 +1,20 @@
+>c+0#00e0003#ffffff0|l|a|s@1| +0#0000000&|C|o|n|t|e|x|t|u|a|l|K|e|y|w|o|r|d|s|T|e|s|t|s| @6|/+0#0000e05&@1| |S|e@1| |J|L|S|,| |§|3|.|9| |K|e|y|w|o|r|d|s|.| +0#0000000&@12
+|{| @73
+@4|p+0#00e0003&|r|i|v|a|t|e| +0#0000000&|C|o|n|t|e|x|t|u|a|l|K|e|y|w|o|r|d|s|T|e|s|t|s|(|)| |{| |t+0#af5f00255&|h|r|o|w| +0#0000000&|n+0#af5f00255&|e|w| +0#0000000&|E|r@1|o|r|(|)|;| |}| @14
+@75
+@4|/+0#0000e05&@1| |M|o|d|u|l|e|D|e|c|l|a|r|a|t|i|o|n|:| |m|o|d|u|l|e| |o|p|e|n|.| +0#0000000&@36
+@4|v+0#00e0003&|o|i|d| +0#0000000&|m|o|d|u|l|e|(|)| @2|{| |O|b|j|e|c|t| |m|o|d|u|l|e| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @4|w|h|e|n|(|)|;| |}| @17
+@4|v+0#00e0003&|o|i|d| +0#0000000&|o|p|e|n|(|)| |{| |O|b|j|e|c|t| |o|p|e|n| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|m|o|d|u|l|e|(|)|;| |}| @19
+@4|/+0#0000e05&@1| |M|o|d|u|l|e|D|i|r|e|c|t|i|v|e|:| |e|x|p|o|r|t|s| |o|p|e|n|s| |p|r|o|v|i|d|e|s| |r|e|q|u|i|r|e|s| |t|o| |u|s|e|s| |w|i|t|h|.| +0#0000000&@5
+@4|v+0#00e0003&|o|i|d| +0#0000000&|e|x|p|o|r|t|s|(|)| @1|{| |O|b|j|e|c|t| |e|x|p|o|r|t|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @3|o|p|e|n|(|)|;| |}| @17
+@4|v+0#00e0003&|o|i|d| +0#0000000&|o|p|e|n|s|(|)| @3|{| |O|b|j|e|c|t| |o|p|e|n|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @5|e|x|p|o|r|t|s|(|)|;| |}| @14
+@4|v+0#00e0003&|o|i|d| +0#0000000&|p|r|o|v|i|d|e|s|(|)| |{| |O|b|j|e|c|t| |p|r|o|v|i|d|e|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @2|o|p|e|n|s|(|)|;| |}| @16
+@4|v+0#00e0003&|o|i|d| +0#0000000&|r|e|q|u|i|r|e|s|(|)| |{| |O|b|j|e|c|t| |r|e|q|u|i|r|e|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @2|p|r|o|v|i|d|e|s|(|)|;| |}| @13
+@4|v+0#00e0003&|o|i|d| +0#0000000&|t|o|(|)| @2|{| |O|b|j|e|c|t| |t|o| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @4|r|e|q|u|i|r|e|s|(|)|;| |}| @21
+@4|v+0#00e0003&|o|i|d| +0#0000000&|u|s|e|s|(|)| |{| |O|b|j|e|c|t| |u|s|e|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|t|o|(|)|;| |}| @23
+@4|v+0#00e0003&|o|i|d| +0#0000000&|w|i|t|h|(|)| |{| |O|b|j|e|c|t| |w|i|t|h| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|u|s|e|s|(|)|;| |}| @21
+@4|/+0#0000e05&@1| |R|e|q|u|i|r|e|s|M|o|d|i|f|i|e|r|:| |t|r|a|n|s|i|t|i|v|e|.| +0#0000000&@38
+@4|v+0#00e0003&|o|i|d| +0#0000000&|t|r|a|n|s|i|t|i|v|e|(|)| |{| |O|b|j|e|c|t| |t|r|a|n|s|i|t|i|v|e| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @2|w|i|t|h|(|)|;| |}| @13
+@4|/+0#0000e05&@1| |L|o|c|a|l|V|a|r|i|a|b|l|e|T|y|p|e| ||| |L|a|m|b|d|a|P|a|r|a|m|e|t|e|r|T|y|p|e|:| |v|a|r|.| +0#0000000&@22
+@4|v+0#00e0003&|o|i|d| +0#0000000&|v|a|r|(|)| @1|{| |v+0#af5f00255&|a|r| +0#0000000&|v+0#af5f00255&|a|r| +0#0000000&|=| |n+0#af5f00255&|e|w| +0#0000000&|O|b|j|e|c|t|(|)|;| @2|t|r|a|n|s|i|t|i|v|e|(|)|;| |}| @15
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/java_contextual_keywords_01.dump b/runtime/syntax/testdir/dumps/java_contextual_keywords_01.dump
new file mode 100644
index 0000000000..5350984ca9
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_contextual_keywords_01.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|v+0#00e0003&|o|i|d| +0#0000000&|u|s|e|s|(|)| |{| |O|b|j|e|c|t| |u|s|e|s| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|t|o|(|)|;| |}| @23
+@4|v+0#00e0003&|o|i|d| +0#0000000&|w|i|t|h|(|)| |{| |O|b|j|e|c|t| |w|i|t|h| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|u|s|e|s|(|)|;| |}| @21
+@4|/+0#0000e05&@1| |R|e|q|u|i|r|e|s|M|o|d|i|f|i|e|r|:| |t|r|a|n|s|i|t|i|v|e|.| +0#0000000&@38
+@4|v+0#00e0003&|o|i|d| +0#0000000&|t|r|a|n|s|i|t|i|v|e|(|)| |{| |O|b|j|e|c|t| |t|r|a|n|s|i|t|i|v|e| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @2|w|i|t|h|(|)|;| |}| @13
+@4|/+0#0000e05&@1| |L|o|c|a|l|V|a|r|i|a|b|l|e|T|y|p|e| ||| |L|a|m|b|d|a|P|a|r|a|m|e|t|e|r|T|y|p|e|:| |v|a|r|.| +0#0000000&@22
+@4>v+0#00e0003&|o|i|d| +0#0000000&|v|a|r|(|)| @1|{| |v+0#af5f00255&|a|r| +0#0000000&|v+0#af5f00255&|a|r| +0#0000000&|=| |n+0#af5f00255&|e|w| +0#0000000&|O|b|j|e|c|t|(|)|;| @2|t|r|a|n|s|i|t|i|v|e|(|)|;| |}| @15
+@4|/+0#0000e05&@1| |Y|i|e|l|d|S|t|a|t|e|m|e|n|t|:| |y|i|e|l|d| |(|s|e@1| |j|a|v|a|_|s|w|i|t|c|h|.|j|a|v|a|)|.| +0#0000000&@22
+@4|v+0#00e0003&|o|i|d| +0#0000000&|y+0#af5f00255&|i|e|l|d|(+0#0000000&|)| @3|{| |O|b|j|e|c|t| |y+0#af5f00255&|i|e|l|d| +0#0000000&|=| |n+0#e000002&|u|l@1|;+0#0000000&| @5|v|a|r|(|)|;| |}| @18
+@4|/+0#0000e05&@1| |R|e|c|o|r|d|D|e|c|l|a|r|a|t|i|o|n|:| |r|e|c|o|r|d|.| +0#0000000&@41
+@4|v+0#00e0003&|o|i|d| +0#0000000&|r|e|c|o|r|d|(|)| @2|{| |O|b|j|e|c|t| |r+0#00e0003&|e|c|o|r|d| +0#0000000&|=| |n+0#e000002&|u|l@1|;+0#0000000&| @4|t+0#00e0003&|h|i|s|.+0#0000000&|y|i|e|l|d|(|)|;| |}| @11
+@4|/+0#0000e05&@1| |N|o|r|m|a|l|{|C|l|a|s@1|,|I|n|t|e|r|f|a|c|e|}|D|e|c|l|a|r|a|t|i|o|n|:| |n|o|n|-|s|e|a|l|e|d| |p|e|r|m|i|t|s| |s|e|a|l|e|d|.| +0#0000000&@5
+@4|v+0#00e0003&|o|i|d| +0#0000000&|p|e|r|m|i|t|s|(|)| @1|{| |O|b|j|e|c|t| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|=| |n+0#e000002&|u|l@1|;+0#0000000&| @3|r|e|c|o|r|d|(|)|;| |}| @15
+@4|v+0#00e0003&|o|i|d| +0#0000000&|s|e|a|l|e|d|(|)| @2|{| |O|b|j|e|c|t| |s+0#4040ff13&|e|a|l|e|d| +0#0000000&|=| |n+0#e000002&|u|l@1|;+0#0000000&| @4|p|e|r|m|i|t|s|(|)|;| |}| @14
+@4|/+0#0000e05&@1| |G|u|a|r|d|:| |w|h|e|n| |(|s|e@1| |j|a|v|a|_|s|w|i|t|c|h|.|j|a|v|a|)|.| +0#0000000&@32
+@4|v+0#00e0003&|o|i|d| +0#0000000&|w|h|e|n|(|)| |{| |O|b|j|e|c|t| |w|h|e|n| |=| |n+0#e000002&|u|l@1|;+0#0000000&| @6|s|e|a|l|e|d|(|)|;| |}| @19
+@75
+@4|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|1| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|1|,| |I|3| |{| |}| @32
+@4|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|2| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|1|,| |I|3| |{| |}| @32
+@4|n+0#4040ff13&|o|n|-|s|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|3| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|I|1|,| |I|2| |{| |}| @28
+@57|1|9|,|2|-|5| @7|4@1|%| 
diff --git a/runtime/syntax/testdir/dumps/java_contextual_keywords_02.dump b/runtime/syntax/testdir/dumps/java_contextual_keywords_02.dump
new file mode 100644
index 0000000000..1e0c363917
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_contextual_keywords_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|n+0#4040ff13&|o|n|-|s|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|3| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|I|1|,| |I|2| |{| |}| @28
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|4| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|I|3| |{| |}| @43
+@75
+@4|a+0#4040ff13&|b|s|t|r|a|c|t| +0#0000000&|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|1| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|1|,| |I|2| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|2|,| |C|3| |{| |}| @9
+@4|a+0#4040ff13&|b|s|t|r|a|c|t| +0#0000000&|n+0#4040ff13&|o|n|-|s|e|a|l|e|d| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|2| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|1| |{| |}| @27
+@4>f+0#4040ff13&|i|n|a|l| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|3| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|1| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |}| @27
+@4|c+0#00e0003&|l|a|s@1| +0#0000000&|C|4| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|2| |{| |}| @47
+@75
+@4|r+0#00e0003&|e|c|o|r|d| +0#0000000&|R|(|)| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |}| @42
+@4|e+0#00e0003&|n|u|m| +0#0000000&|E| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |I|N|S|T|A|N|C|E| |}| @37
+@75
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|1|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|v+0#af5f00255&|a|r| +0#0000000&|v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @21
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|2|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|T| |v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @23
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|3|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @25
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|4|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|v+0#af5f00255&|a|r| +0#0000000&|-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @27
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|<|T|>| |{| |T| |i|(|T| |i|)|;| |d+0#4040ff13&|e|f|a|u|l|t| +0#0000000&|I|<|T|>| |s|e|l|f|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|t+0#00e0003&|h|i|s|;+0#0000000&| |}| |}| @5
+|}| @73
+|~+0#4040ff13&| @73
+|~| @73
+| +0#0000000&@56|3|7|,|2|-|5| @7|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/java_contextual_keywords_99.dump b/runtime/syntax/testdir/dumps/java_contextual_keywords_99.dump
new file mode 100644
index 0000000000..b429c8192c
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_contextual_keywords_99.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|1| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|1|,| |I|3| |{| |}| @32
+@4|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|2| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|1|,| |I|3| |{| |}| @32
+@4|n+0#4040ff13&|o|n|-|s|e|a|l|e|d| +0#0000000&|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|3| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|I|1|,| |I|2| |{| |}| @28
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|4| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|I|3| |{| |}| @43
+@75
+@4|a+0#4040ff13&|b|s|t|r|a|c|t| +0#0000000&|s+0#4040ff13&|e|a|l|e|d| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|1| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|1|,| |I|2| |p+0#00e0003&|e|r|m|i|t|s| +0#0000000&|C|2|,| |C|3| |{| |}| @9
+@4|a+0#4040ff13&|b|s|t|r|a|c|t| +0#0000000&|n+0#4040ff13&|o|n|-|s|e|a|l|e|d| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|2| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|1| |{| |}| @27
+@4|f+0#4040ff13&|i|n|a|l| +0#0000000&|c+0#00e0003&|l|a|s@1| +0#0000000&|C|3| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|1| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |}| @27
+@4|c+0#00e0003&|l|a|s@1| +0#0000000&|C|4| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|C|2| |{| |}| @47
+@75
+@4|r+0#00e0003&|e|c|o|r|d| +0#0000000&|R|(|)| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |}| @42
+@4|e+0#00e0003&|n|u|m| +0#0000000&|E| |i+0#00e0003&|m|p|l|e|m|e|n|t|s| +0#0000000&|I|3| |{| |I|N|S|T|A|N|C|E| |}| @37
+@75
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|1|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|v+0#af5f00255&|a|r| +0#0000000&|v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @21
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|2|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|T| |v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @23
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|3|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|(|v+0#af5f00255&|a|r|)+0#0000000&| |-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @25
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|<|T|>| |I|<|T|>| |i|4|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|v+0#af5f00255&|a|r| +0#0000000&|-|>| |v+0#af5f00255&|a|r|;+0#0000000&| |}| @27
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|<|T|>| |{| |T| |i|(|T| |i|)|;| |d+0#4040ff13&|e|f|a|u|l|t| +0#0000000&|I|<|T|>| |s|e|l|f|(|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|t+0#00e0003&|h|i|s|;+0#0000000&| |}| |}| @5
+>}| @73
+@57|4|8|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/input/java_contextual_keywords.java b/runtime/syntax/testdir/input/java_contextual_keywords.java
new file mode 100644
index 0000000000..094037964c
--- /dev/null
+++ b/runtime/syntax/testdir/input/java_contextual_keywords.java
@@ -0,0 +1,48 @@
+class ContextualKeywordsTests		// See JLS, §3.9 Keywords.
+{
+	private ContextualKeywordsTests() { throw new Error(); }
+
+	// ModuleDeclaration: module open.
+	void module()	{ Object module = null;		when(); }
+	void open()	{ Object open = null;		module(); }
+	// ModuleDirective: exports opens provides requires to uses with.
+	void exports()	{ Object exports = null;	open(); }
+	void opens()	{ Object opens = null;		exports(); }
+	void provides()	{ Object provides = null;	opens(); }
+	void requires()	{ Object requires = null;	provides(); }
+	void to()	{ Object to = null;		requires(); }
+	void uses()	{ Object uses = null;		to(); }
+	void with()	{ Object with = null;		uses(); }
+	// RequiresModifier: transitive.
+	void transitive() { Object transitive = null;	with(); }
+	// LocalVariableType | LambdaParameterType: var.
+	void var()	{ var var = new Object();	transitive(); }
+	// YieldStatement: yield (see java_switch.java).
+	void yield()	{ Object yield = null;		var(); }
+	// RecordDeclaration: record.
+	void record()	{ Object record = null;		this.yield(); }
+	// Normal{Class,Interface}Declaration: non-sealed permits sealed.
+	void permits()	{ Object permits = null;	record(); }
+	void sealed()	{ Object sealed = null;		permits(); }
+	// Guard: when (see java_switch.java).
+	void when()	{ Object when = null;		sealed(); }
+
+	sealed interface I1 permits C1, I3 { }
+	sealed interface I2 permits C1, I3 { }
+	non-sealed interface I3 extends I1, I2 { }
+	interface I4 extends I3 { }
+
+	abstract sealed class C1 implements I1, I2 permits C2, C3 { }
+	abstract non-sealed class C2 extends C1 { }
+	final class C3 extends C1 implements I3 { }
+	class C4 extends C2 { }
+
+	record R() implements I3 { }
+	enum E implements I3 { INSTANCE }
+
+	static <T> I<T> i1() { return (var var) -> var; }
+	static <T> I<T> i2() { return (T var) -> var; }
+	static <T> I<T> i3() { return (var) -> var; }
+	static <T> I<T> i4() { return var -> var; }
+	interface I<T> { T i(T i); default I<T> self() { return this; } }
+}