Update atomicops_internals_arm64_gcc with changes made in chromium base/

BUG=354405
LOG=N
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/212673006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20288 ce2b1a6d-e550-0410-aec6-3dcde31c8c00