Make Object.freeze fast
This patch both speeds up the freeze operation itself, but also
allows properties to remain in fast mode. Objects with non-empty
elements backing stores still end up with slow elements.
Relanding r14758 and r14759 with fix for Test262: only mark properties
and elements READ_ONLY if they are not JS setter/getters. Tightened up
tests to assert frozen-ness, and added targeted tests for the new code
(covering accessors).
BUG=v8:1858, 115960
R=verwaest@chromium.org
Review URL: https://chromiumcodereview.appspot.com/
15691007
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14762
ce2b1a6d-e550-0410-aec6-
3dcde31c8c00