don't preserve names on IR instructions. This matches llvm-gcc's behavior and

speeds up the compiler by ~8% at -emit-llvm -O0.

llvm-svn: 58977

clang/lib/CodeGen/CGBuilder.h

@@ -14,7 +14,8 @@
 
 namespace clang {
 namespace CodeGen {
-  typedef llvm::IRBuilder<> CGBuilderTy;
+  // Don't preserve names on values by default.
+  typedef llvm::IRBuilder<false> CGBuilderTy;
 }  // end namespace CodeGen
 }  // end namespace clang