Revert r220779, "[AVX512] Removed special case for cmp instructions in getVectorMaskingNode. Now cmp intrinsics lower as other intrinsics through VSELECT, and then VSELECT tranforms to AND in PerformSELECTCombine."

Since r221028 (reverting r220777), this caused failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221040 91177308-0d34-0410-b5e6-96231b3b80d8