7133093: Improve system dictionary performance
Summary: implement one dictionary per ClassLoaderData for faster lookup and removal during class unloading
Reviewed-by: iklam, acorn, jiangli
8183039: Re-examine methodHandle methods uninlined by 8144256
Summary: Add more const references so out-of-line methodHandle destructor and copy ctor called infrequently
Reviewed-by: hseigel, redestad