Add an obvious missing safety check to DAE::RemoveDeadArgumentsFromCallers.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126720 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index b423221..4d1f7ab 100644
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -294,7 +294,7 @@
 /// instead.
 bool DAE::RemoveDeadArgumentsFromCallers(Function &Fn)
 {
-  if (Fn.isDeclaration())
+  if (Fn.isDeclaration() || Fn.mayBeOverridden())
     return false;
 
   // Functions with local linkage should already have been handled.