Add tests for GlobalHandles::IterateObjectGroups.

test/cctest/cctest.gyp

 # Copyright 2012 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 52 matching lines @@
         'test-decls.cc',
         'test-deoptimization.cc',
         'test-dictionary.cc',
         'test-diy-fp.cc',
         'test-double.cc',
         'test-dtoa.cc',
         'test-fast-dtoa.cc',
         'test-fixed-dtoa.cc',
         'test-flags.cc',
         'test-func-name-inference.cc',
+        'test-global-handles.cc',
         'test-global-object.cc',
         'test-hashing.cc',
         'test-hashmap.cc',
         'test-heap.cc',
         'test-heap-profiler.cc',
         'test-list.cc',
         'test-liveedit.cc',
         'test-lock.cc',
         'test-lockers.cc',
         'test-log.cc',
@@ skipping 114 matching lines @@
             '<@(_outputs)',
             'TEST',  # type
             'off',  # compression
             '<@(file_list)',
           ],
         }
       ],
     },
   ],
 }