Annotate a lot of X86InstrInfo.td with SchedRW lists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177417 91177308-0d34-0410-b5e6-96231b3b80d8
Annotate X86InstrExtension.td with SchedRW lists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177418 91177308-0d34-0410-b5e6-96231b3b80d8