Add back a couple checks removed by r129128; the fact that an intitializer
is an array of structures doesn't imply it's a ConstantArray of
ConstantStruct.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129207 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 5b6ed2c..71d13ed 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1954,11 +1954,13 @@
   // only allowed to optimize the initializer if it is unique.
   if (!GV->hasUniqueInitializer()) return 0;
   
-  ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
-  
+  ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
+  if (!CA) return 0;
+
   for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
-    ConstantStruct *CS = cast<ConstantStruct>(*i);
-    
+    ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
+    if (!CS) return 0;
+
     if (isa<ConstantPointerNull>(CS->getOperand(1)))
       continue;