To be able to successfully build OpenMP on 32-bit FreeBSD, such as
FreeBSD/i386, I first had to provide a few wrappers (see D60916), and
then add KMP_OS_FREEBSD to the list of defines checked for 32-bit
architectures in kmp_runtime.cpp.
I have successfully built libomp.so and ran a bunch of test programs on
FreeBSD/i386 with this.