[X86] Remove masked vpermi2var/vpermt2var intrinsics and autoupgrade.

We have unmasked intrinsics now and wrap them with a select. This is a net reduction of 36 intrinsics from before the unmasked intrinsics were added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333388 91177308-0d34-0410-b5e6-96231b3b80d8
19 files changed