use CodeGenModule::EmitNullConstant in a couple of places.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77915 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 7028e74..9fd571b 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -105,9 +105,8 @@
   const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
   return new llvm::GlobalVariable(CGM.getModule(), LTy,
                                   Ty.isConstant(getContext()), Linkage,
-                                  llvm::Constant::getNullValue(LTy), Name,
-                                  0, D.isThreadSpecified(),
-                                  Ty.getAddressSpace());
+                                  CGM.EmitNullConstant(D.getType()), Name, 0, 
+                                  D.isThreadSpecified(), Ty.getAddressSpace());
 }
 
 void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {