[x86] Change AVX512 intrinsics to take a 8-bit immediate for the comparision kind instead of a 32-bit immediate. This better aligns with the emitted instruction. It also matches SSE and AVX1 equivalents. Also add auto upgrade support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226430 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed