[WebAssembly] Set ctlz_zero_undef/cttz_zero_undef to Expand so LegalizeDAG will convert them to ctlz/cttz. Remove the now unneccessary isel patterns. NFC

llvm-svn: 267264
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 4839a32..dadd312 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -97,7 +97,7 @@
          {ISD::BSWAP, ISD::SMUL_LOHI, ISD::UMUL_LOHI,
           ISD::MULHS, ISD::MULHU, ISD::SDIVREM, ISD::UDIVREM, ISD::SHL_PARTS,
           ISD::SRA_PARTS, ISD::SRL_PARTS, ISD::ADDC, ISD::ADDE, ISD::SUBC,
-          ISD::SUBE}) {
+          ISD::SUBE, ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}) {
       setOperationAction(Op, T, Expand);
     }
   }