8186837: Memory ordering nmethod, _state and _stack_traversal_mark Reviewed-by: dholmes, rkennke

8164207: Checking missing load-acquire in relation to _pd_set in dictionary.cpp Summary: Use load_acquire for accessing DictionaryEntry::_pd_set since it's accessed outside the SystemDictionary_lock Reviewed-by: zgu, twisti, dholmes, adinn

8186797: cardtable_rs in g1CollectedHeap::initialize() defined, but never used Reviewed-by: tschatzl, ehelin