Update for LLVM API change.

llvm-svn: 77722
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index d3dc9c8..ea0057e 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -360,7 +360,7 @@
 void AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) {
   if (!CGF.hasAggregateLLVMType(T)) {
     // For non-aggregates, we can store zero
-    llvm::Value *Null = CGF.getLLVMContext().getNullValue(CGF.ConvertType(T));
+    llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T));
     CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T);
   } else {
     // Otherwise, just memset the whole thing to zero.  This is legal