QWARN : qscriptcontext_impl_p.h:197: QScriptPassPointer<QScriptValuePrivate> QScriptContextPrivate::callee() const: Unimplemented code.

Autotest: tst_QScriptContext::pushAndPopContext()

Calling callee() on a QScriptContext that isn't associated with a
function call (for which we have V8::Arguments). When we have
V8::AccessorInfo we may want to return something, for other cases we can
return an invalid value.