[X86] Use tablegen instead of DAG combines to match BZHI instructions, as
suggested by Ben Kramer in review of r206738.

Thanks again Ben!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206879 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed