Reviewed my Maciej Stachowiak

This adds new methods fastMallocExecutable and fastFreeExecutable
to wrap allocation for cti code.  This still just makes fastMalloc
return executable memory all the time, which will be fixed in a
later patch.

However in windows debug builds all executable allocations will be
allocated on separate executable pages, which should resolve any
remaining 2k3 issues.  Conveniently the 2k3 bot will now also fail
if there are any fastFree vs. fastFreeExecutable errors.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@37804 268f45cc-cd09-0410-ab3c-d52691b4dbfc