jdk

d874e961 - 8271579: G1: Move copy before CAS in do_copy_to_survivor_space

8271579: G1: Move copy before CAS in do_copy_to_survivor_space 8272070: G1: Simplify age calculation after JDK-8271579 Co-authored-by: shoubing ma <mashoubing1@huawei.com> Reviewed-by: tschatzl, ayang