[libc][CI] unanticipated macro expansion of clearerr_unlocked in macos-15 build

[bojle]

See https://github.com/llvm/llvm-project/actions/runs/20103522181/job/57680755758

Macos sdk defines clearerr_unlocked as a macro and file.h defines it as a function. When running on macos, the preprocessor erroneously substitutes the defintion for the macro in place of the function identifier causing build failures.

[llvmbot]

@llvm/issue-subscribers-libc

Author: Shreeyash Pandey (bojle)

Details

See https://github.com/llvm/llvm-project/actions/runs/20103522181/job/57680755758

Macos sdk defines clearerr_unlocked as a macro and file.h defines it as a function. When running on macos, the preprocessor erroneously substitutes the defintion for the macro in place of the function identifier causing build failures.