[X86] Improve the unknown stepping support for Intel CPUs in getHostCPUName

This patch improves our guessing of unknown Intel CPUs to support Goldmont and skylake-avx512.

Differential Revision: https://reviews.llvm.org/D35161

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309246 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed