Ensure that external symbols have hash codes.

src/heap.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2124 matching lines @@
   // have to patch the external string resource after the callback.
   DummyExternalStringResource dummy_resource(chars);
   Object* obj = AllocateExternalSymbolFromTwoByte(&dummy_resource);
   if (obj->IsFailure()) return obj;
   // Perform callback.
   v8::String::ExternalStringResource* resource =
       global_external_symbol_callback_(string.start(), string.length());
   // Patch the resource pointer of the result.
   ExternalTwoByteString* result = ExternalTwoByteString::cast(obj);
   result->set_resource(resource);
+  // Force hash code to be computed.
+  result->Hash();
   ASSERT(result->IsEqualTo(string));
   return result;
 }
 
 
 Object* Heap::AllocateRawAsciiString(int length, PretenureFlag pretenure) {
   AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE;
   int size = SeqAsciiString::SizeFor(length);
   if (size > MaxHeapObjectSize()) {
     space = LO_SPACE;
@@ skipping 1157 matching lines @@
 #ifdef DEBUG
 bool Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (Bootstrapper::IsActive()) return true;
   if (disallow_allocation_failure()) return true;
   return CollectGarbage(0, NEW_SPACE);
 }
 #endif
 
 } }  // namespace v8::internal