[X86] Use update_llc_test_checks.py to regenerate a test and add command lines...

[X86] Use update_llc_test_checks.py to regenerate a test and add command lines to demonstrate that we don't pick EVEX encoded instruction when AVX512 and FMA3 are both enabled.

This bug only exists on the scalar llvm.fma instrinsics. Looks like we don't test the llvm.fma intrinsics very thoroughly. In fact I don't see any tests for the vector versions.

llvm-svn: 298045