fix CreateTempAlloca to not set a name on the alloca for temporaries
in release-assert builds.  For automatic variables, explicitly set
a name with setName that does not make a temporary std::string.

This speeds up -emit-llvm-only -disable-free on PR3810 by 4.6%


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67459 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 8a4febe..49ac20a 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -232,8 +232,9 @@
       const llvm::Type *LTy = ConvertTypeForMem(Ty);
       if (isByRef)
         LTy = BuildByRefType(Ty, getContext().getDeclAlignInBytes(&D));
-      llvm::AllocaInst *Alloc = 
-        CreateTempAlloca(LTy, D.getNameAsString().c_str());
+      llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
+      Alloc->setName(D.getNameAsString().c_str());
+      
       if (isByRef)
         Alloc->setAlignment(std::max(getContext().getDeclAlignInBytes(&D),
                                      getContext().getTypeAlign(getContext().VoidPtrTy) / 8));
@@ -429,7 +430,8 @@
       // TODO: Alignment
       std::string Name = D.getNameAsString();
       Name += ".addr";
-      DeclPtr = CreateTempAlloca(LTy, Name.c_str());
+      DeclPtr = CreateTempAlloca(LTy);
+      DeclPtr->setName(Name.c_str());
       
       // Store the initial value into the alloca.
       EmitStoreOfScalar(Arg, DeclPtr, Ty.isVolatileQualified());