commonlib: Clean up compiler.h

This patch contains several minor cleanups related to compiler.h:

- Replace __always_unused() (which is a Linux-specific concept that
  doesn't make sense without also having __maybe_unused(), and had zero
  uses in the codebase) with __unused() which moves here from helpers.h

- Add __underscores__ to the names of all attributes in the compiler
  attribute shorthand macros. This is necessary to make them work in
  files where the same name was already used for an identifier (e.g.
  cbfstool/cbfs.h's `unused` array of file types).

- Remove libpayload's own copy of compiler.h and make it directly pull
  in the commonlib/bsd copy.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I9644da594bb69133843c6b7f12ce50b2e45fd24b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64737
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>

0 files changed, 0 insertions, 0 deletions