6627983: G1: Bad oop deference during marking Summary: Bulk zeroing reduction didn't work with G1, because arraycopy would call pre-barriers on uninitialized oops. The solution is to have version of arraycopy stubs that don't have pre-barriers. Also refactored arraycopy stubs generation on SPARC to be more readable and reduced the number of stubs necessary in some cases. Reviewed-by: jrose, kvn, never

6725983: Assertion "method->method_holder())->is_not_initialized(),"method holder must be initialized" Reviewed-by: kvn, iveresov