Update Clang for 3.5 rebase (r209713).

Change-Id: I8c9133b0f8f776dc915f270b60f94962e771bc83
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 1f84c86..7244b9e 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -306,7 +306,7 @@
   unsigned ComplexAlign = C.getTypeAlignInChars(ComplexTy).getQuantity();
   unsigned AlignI = std::min(AlignR, ComplexAlign);
 
-  llvm::Value *Real=0, *Imag=0;
+  llvm::Value *Real=nullptr, *Imag=nullptr;
 
   if (!IgnoreReal || isVolatile) {
     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,