Merge

8186248: Allow more flexibility in selecting Heap % of available RAM Reviewed-by: dholmes, drwhite

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