https://bugs.webkit.org/show_bug.cgi?id=69677

Reviewed by Sam Weinig.

Source/JavaScriptCore:

Removed toString from JSCallbackObject, since it is no
longer necessary since we now implicitly add toString and valueOf
functions to object prototypes when a convertToType callback
is provided, which is now the standard way to override toString
and valueOf in the JSC C API.
* API/JSCallbackObject.h:
* API/JSCallbackObjectFunctions.h:
* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.def:

Removed toString from InterruptedExecutionError and
TerminatedExecutionError and replaced it with defaultValue,
which JSObject::toString calls.  We'll probably have to de-virtualize
defaultValue eventually, but we'll cross that bridge when we
come to it.
* runtime/ExceptionHelpers.cpp:
(JSC::InterruptedExecutionError::defaultValue):
(JSC::TerminatedExecutionError::defaultValue):
* runtime/ExceptionHelpers.h:

Removed toString from JSNotAnObject, since its return value doesn't
actually matter and JSObject::toString can cover it.
* runtime/JSNotAnObject.cpp:
* runtime/JSNotAnObject.h:

De-virtualized JSCell::toString, JSObject::toString and JSString::toString.
Added handling of all cases for JSCell to JSCell::toString.
* runtime/JSObject.h:
* runtime/JSString.h:
* runtime/JSCell.cpp:
(JSC::JSCell::toString):
* runtime/JSCell.h:

Source/JavaScriptGlue:

Removed UserObjectImp::toString because it's no longer necessary since
clients can provide their own toString callback which will in turn be
called by JSObject::toString.
* UserObjectImp.cpp:
* UserObjectImp.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@97292 268f45cc-cd09-0410-ab3c-d52691b4dbfc