Fix use-after-free.

llvm-svn: 241121
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 0dea3a8..8cf87a3 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1294,8 +1294,9 @@
   void GenerateThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
                      GlobalDecl GD, const ThunkInfo &Thunk);
 
-  void GenerateVarArgsThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
-                            GlobalDecl GD, const ThunkInfo &Thunk);
+  llvm::Function *GenerateVarArgsThunk(llvm::Function *Fn,
+                                       const CGFunctionInfo &FnInfo,
+                                       GlobalDecl GD, const ThunkInfo &Thunk);
 
   void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
                         FunctionArgList &Args);