[Lanai] Set CTLZ_ZERO_UNDEF/CTTZ_ZERO_UNDEF to Expand instead of Legal so they will be converted to CTLZ/CTTZ by LegalizeDAG. Remove extra instructions that only existed to to contain patterns that match the zero_undef operations. NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267108 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed