ffi-macros: New crate.

  - This crate contains macros for Sequoia's FFI crate(s).  Having it
    in a separate crate means that we can share it when we split the
    FFI crate into two.

  - More importantly, we need a separate crate if we want to create
    procedural macros.

  - As first macro, this patch adds ffi_catch_abort that wraps a
    function's body in a catch_unwind block, aborting on panics.

1 files changed, 1 insertions, 0 deletions

diff --git a/ffi-macros/README.md b/ffi-macros/README.md
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+This is a set of macros to help with the FFI glue for Sequoia.