Enable Object.observe by default

R=rossberg@chromium.org, rossberg
BUG=v8:2409
LOG=Y

Review URL: https://codereview.chromium.org/183683022

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Revert "Enable Object.observe by default"

TBR=rossberg
BUG=

Review URL: https://codereview.chromium.org/190853007

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19735 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Reland "Enable Object.observe by default"

Original Issue: https://codereview.chromium.org/183683022/

TBR=rossberg
BUG=v8:2409
LOG=Y

Review URL: https://codereview.chromium.org/189513010

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19736 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Replace the recursion in PropagateMinusZeroChecks() with a loop and a worklist.

Also refactor the related code in preparation for fixing the
range analysis.

BUG=v8:3204
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/190713002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Atomic ops: Sync with Chromium and add unit test.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/129813008

Patch from Cosmin Truta <ctruta@gmail.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Skip unreachable blocks when looking for next emitted block.

Goto does not emit a jump if the target is the next emitted block.
However, if there is an unreachable block between Goto and the jump
target, we still emit a jump even though the unreachable block is
not actually emitted. That jump is unnecessary.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/174883002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19739 ce2b1a6d-e550-0410-aec6-3dcde31c8c00