temporary workaround for matching inc/dec on x86_64 to the correct instruction.
- This hack will eventually be replaced with a robust mechanism for handling
matching instructions based on the available target features.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98858 91177308-0d34-0410-b5e6-96231b3b80d8