[X86] Remove INVPCID and SMAP feature flags. They aren't currently used by any instructions and not tested.

If we implement intrinsics for their instructions in the future, the feature flags can be added back with proper testing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294561 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed