[test] Make Linux/sem_init_glibc.cpp robust

and fix it for 32-bit ports defining sem_init@GLIBC_2.0 (i386, mips32, powerpc32) for glibc>=2.36.

Fix https://github.com/llvm/llvm-project/issues/58079

Reviewed By: mgorny

Differential Revision: https://reviews.llvm.org/D135023