[CodeGenPrepare][NFC] Rename TargetTransformInfo::expandMemCmp -> TargetTransformInfo::enableMemCmpExpansion.

Summary:
Right now there are two functions with the same name, one does the work
and the other one returns true if expansion is needed. Rename
TargetTransformInfo::expandMemCmp to make it more consistent with other
members of TargetTransformInfo.

Remove the unused Instruction* parameter.

Differential Revision: https://reviews.llvm.org/D38165

llvm-svn: 314096
diff --git a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
index 6110706..d3295a9 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -215,7 +215,7 @@
   return LoopHasReductions;
 }
 
-bool PPCTTIImpl::expandMemCmp(Instruction *I, unsigned &MaxLoadSize) {
+bool PPCTTIImpl::enableMemCmpExpansion(unsigned &MaxLoadSize) {
   MaxLoadSize = 8;
   return true;
 }