Compile error for __builtin_cpu_supports("avx512f")

[hzhou]

          @yfguo This broke build on older systems - e.g. the xpmem CI on yuzu:

src/arch/mpl_arch_x86.c: In function ‘MPL_check_arch_features’:
src/arch/mpl_arch_x86.c:69:5: error: Parameter to builtin not valid: avx512f
     if (__builtin_cpu_supports("avx512f")) {

Originally posted by @hzhou in https://github.com/pmodels/mpich/issues/7361#issuecomment-2864311337

[hzhou]

https://jenkins-pmrs.cels.anl.gov/job/mpich-review-ch4-xpmem/199/jenkins_configure=debug,label=xpmem,netmod=ofi,shmmod=xpmem/console