Fix redefining of attributes on aliased arguments.

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index 6f009970dabc8fbc91ff1bc3bfafc6f26db9b187..7aef91215d3717b1fab69622e62a8468a6fb2449 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -333,6 +333,11 @@ void TypeFeedbackInfo::TypeFeedbackInfoVerify() {
 }
 
 
+void AliasedArgumentsEntry::AliasedArgumentsEntryVerify() {
+  VerifySmiField(kAliasedContextSlot);
+}
+
+
 void FixedArray::FixedArrayVerify() {
   for (int i = 0; i < length(); i++) {
     Object* e = get(i);