Fix a (false) warning on darwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52705 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 6a0d674..4f05f48 100644
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -579,7 +579,7 @@
   // Find out the new return value
 
   const Type *RetTy = FTy->getReturnType();
-  const Type *NRetTy;
+  const Type *NRetTy = NULL;
   unsigned RetCount = NumRetVals(F);
   // Explicitely track if anything changed, for debugging
   bool Changed = false;
@@ -632,6 +632,8 @@
     NRetTy = Type::VoidTy;
   }
 
+  assert(NRetTy && "No new return type found?");
+
   // Remove any incompatible attributes
   RAttrs &= ~ParamAttr::typeIncompatible(NRetTy);
   if (RAttrs)