The Glibc header [1] define _ABIO32 unconditionally on MIPS. So we need
to compare _MIPS_SIM and _ABIO32 to know if we are actually building for
MIPS32. Using sanitizer_atomic_clang_mips.h can cause test failures and
hangs on MIPS64.
[1]:https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/mips/sgidefs.h