Change CallFrame::lexicalGlobalObject() to use Callee instead of JSScope
https://bugs.webkit.org/show_bug.cgi?id=136901

Reviewed by Mark Lam.

Implement ExecState::lexicalGlobalObject() using Callee.
        
* runtime/JSScope.h:
(JSC::ExecState::lexicalGlobalObject):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@175118 268f45cc-cd09-0410-ab3c-d52691b4dbfc