Read object pointer atomically while updating slots

BUG=425003
R=ulan@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/663023002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Annotate PromotionQueue::RelocateQueueHead for MemorySanitizer.

BUG=chromium:416875
LOG=N
R=earthdok@chromium.org, jkummerow@chromium.org

Review URL: https://codereview.chromium.org/603633002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove fuzz-natives tests.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/663043003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24739 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Upgrade test262-es6

R=dslomov@chromium.org
BUG=

Review URL: https://codereview.chromium.org/639373005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24740 ce2b1a6d-e550-0410-aec6-3dcde31c8c00