X86: Rename the CLMUL target feature to PCLMUL.

It was renamed in gcc/gas a while ago and causes all kinds of
confusion because it was named differently in llvm and clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157745 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed