Support the [Supplemental] IDL for constants

Support the [Supplemental] IDL for constants
https://bugs.webkit.org/show_bug.cgi?id=77228

Reviewed by Adam Barth.

We have supported the [Supplemental] IDL for attributes and methods.
This patch supports it for constants.

Test: bindings/scripts/test/TestSupplemental.idl

* bindings/scripts/generate-bindings.pl:
Supported [Supplemental] constants.
Updated some comments.

* bindings/scripts/test/TestSupplemental.idl:
Added test cases for [Supplemental] constants.

* bindings/scripts/test/CPP/WebDOMTestInterface.h: Updated the test results.
* bindings/scripts/test/JS/JSTestInterface.cpp: Ditto.
(WebCore::JSTestInterfacePrototype::getOwnPropertySlot):
(WebCore::JSTestInterfacePrototype::getOwnPropertyDescriptor):
(WebCore):
(WebCore::jsTestInterfaceSUPPLEMENTAL_CONSTANT1):
(WebCore::jsTestInterfaceSUPPLEMENTAL_CONSTANT2):
* bindings/scripts/test/JS/JSTestInterface.h: Ditto.
(WebCore):
* bindings/scripts/test/ObjC/DOMTestInterface.h: Ditto.
* bindings/scripts/test/V8/V8TestInterface.cpp: Ditto.
(WebCore::ConfigureV8TestInterfaceTemplate):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106140 268f45cc-cd09-0410-ab3c-d52691b4dbfc