Replace OS::NumberOfCores() with CPU::NumberOfProcessorsOnline().

The name NumberOfCores is misleading, as it does not return the
actual number of cores. While NumberOfProcessorsOnline is also
not a great name, it's at least consistent with the operating
system terminology.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/23655004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16392 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Insert allocation memento clear instructions after the dominating allocate instruction.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/23672004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16393 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix lost store side effects with escape analysis.

This preserves side effects from stores in HCapturedObject markers so
that simulates following these markers are not merged away.

R=titzer@chromium.org
TEST=mjsunit/compiler/escape-analysis --deopt-every-n-times [3,6,9]

Review URL: https://codereview.chromium.org/23554003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16394 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Simplify logic by extracting local lookup before the switch.

R=rossberg@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22901034

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16395 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge verbatim descriptors from other (the descriptor of the map being updated) rather than this (descriptors of the most updated map found in the transition tree).

BUG=v8:2863
R=svenpanne@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23676003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16396 ce2b1a6d-e550-0410-aec6-3dcde31c8c00