Implement review feedback

llvm-svn: 36564
diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index c580e70..8e632e2 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -321,7 +321,8 @@
   
   if (!isa<GlobalValue>(GA.getAliasee())) {
     const ConstantExpr *CE = dyn_cast<ConstantExpr>(GA.getAliasee());
-    Assert1(CE && CE->getOpcode() == Instruction::BitCast,
+    Assert1(CE && CE->getOpcode() == Instruction::BitCast &&
+            isa<GlobalValue>(CE->getOperand(0)),
             "Aliasee should be either GlobalValue or bitcast of GlobalValue",
             &GA);
   }