Do not allow external strings in old pointer space.

test/cctest/cctest.status

 # Copyright 2011 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 24 matching lines @@
 test-api/ApplyInterruption: PASS || TIMEOUT
 
 # These tests always fail.  They are here to test test.py.  If
 # they don't fail then test.py has failed.
 test-serialize/TestThatAlwaysFails: FAIL
 test-serialize/DependentTestThatAlwaysFails: FAIL
 
 # This test always fails.  It tests that LiveEdit causes abort when turned off.
 test-debug/LiveEditDisabled: FAIL
 
-# TODO(yangguo,mstarzinger): Fix bug in String::MakeExternal.
-test-api/MakingExternalUnalignedAsciiString: PASS || CRASH
-
 # TODO(gc): Temporarily disabled in the GC branch.
 test-log/EquivalenceOfLoggingAndTraversal: PASS || FAIL
 
 # We do not yet shrink weak maps after they have been emptied by the GC
 test-weakmaps/Shrinking: FAIL
 test-weaksets/WeakSet_Shrinking: FAIL
 
 # Boot up memory use is bloated in debug mode.
 test-mark-compact/BootUpMemoryUse: PASS, PASS || FAIL if $mode == debug
 
@@ skipping 55 matching lines @@
 test-log/LogCallbacks: SKIP
 test-log/ProfLazyMode: SKIP
 
 # Native Client doesn't support sockets.
 test-debug/DebuggerAgent: SKIP
 test-debug/DebuggerAgentProtocolOverflowHeader: SKIP
 test-sockets/Socket: SKIP
 
 # Profiling doesn't work on Native Client.
 test-cpu-profiler/*: SKIP