[compiler-rt] [compiler-rt] eventfd api interception on freebsd. (PR #76564)

[David CARLIER via llvm-commits]

devnexen wrote:

in fact the posix one would need more changes, ie [freebsd does not really use it](https://github.com/llvm/llvm-project/blob/273aefec66cea947787f053adee25175f4168713/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h#L17) (e.g. __sanitizer_sigaction defined in the freebsd one but "defined" in the posix too).

https://github.com/llvm/llvm-project/pull/76564