Move verification of builtin_vtables into Dart::InitializeIsolate.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 17246)
+++ runtime/vm/object.h	(working copy)
@@ -353,6 +353,8 @@
     return RoundedAllocationSize(sizeof(RawObject));
   }
 
+  static void VerifyBuiltinVtables();
+
   static const ClassId kClassId = kObjectCid;
 
   // Different kinds of type tests.
@@ -6169,15 +6171,13 @@
   }
   set_vtable(builtin_vtables_[cid]);
 #if defined(DEBUG)
-  Isolate* isolate = Isolate::Current();
   if (FLAG_verify_handles) {
+    Isolate* isolate = Isolate::Current();
     Heap* isolate_heap = isolate->heap();
     Heap* vm_isolate_heap = Dart::vm_isolate()->heap();
     ASSERT(isolate_heap->Contains(RawObject::ToAddr(raw_)) ||
            vm_isolate_heap->Contains(RawObject::ToAddr(raw_)));
   }
-  ASSERT(builtin_vtables_[cid] ==
-         isolate->class_table()->At(cid)->ptr()->handle_vtable_);
 #endif
 }