Move call stack depth counter to global object.

        * kjs/ExecState.h: (KJS::ExecState::functionCallDepth): Added a recursion depth counter to
        per-thread data.
        * kjs/JSGlobalObject.cpp: (KJS::JSGlobalObject::init): Initialize PerThreadData.functionCallDepth.
        * kjs/JSGlobalObject.h: (KJS::JSGlobalObject::perThreadData): Made the result non-const.

        * kjs/object.cpp:
        (KJS::throwStackSizeExceededError): Moved throwError to a separate function, since it is now
        the only thing in JSObject::call that needs a PIC branch.
        (KJS::JSObject::call): Use a per-thread variable instead of local static for recursion depth
        tracking.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@32819 268f45cc-cd09-0410-ab3c-d52691b4dbfc