Update for LLVM API change.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77722 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index b552da6..7028e74 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -105,7 +105,7 @@
   const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
   return new llvm::GlobalVariable(CGM.getModule(), LTy,
                                   Ty.isConstant(getContext()), Linkage,
-                                  VMContext.getNullValue(LTy), Name,
+                                  llvm::Constant::getNullValue(LTy), Name,
                                   0, D.isThreadSpecified(),
                                   Ty.getAddressSpace());
 }