[v8] Enable binding integrity on mac
https://bugs.webkit.org/show_bug.cgi?id=108500

Reviewed by Adam Barth.

Patch is correct if existing tests pass without new crashes.

* features.gypi:
Set ENABLE_BINDING_INTEGRITY=1 when OS=="mac"


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141461 268f45cc-cd09-0410-ab3c-d52691b4dbfc