Return MaybeHandle from JsonParser.

R=ishell@chromium.org

Review URL: https://codereview.chromium.org/223553003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20485 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
ARM64: Fix the atomic type width in the 64bit Acquire_Load().

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/220203012

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00