Add an 'isReadOnly' member to IDL parse tree structure

Add an 'isReadOnly' member to IDL parse tree structure
https://bugs.webkit.org/show_bug.cgi?id=115704

Reviewed by Kentaro Hara.

Source/WebCore:

Add an 'isReadOnly' member to IDL parse tree structure by merging
https://chromium.googlesource.com/chromium/blink/+/d6add80ecd08bcd88a6ae0e1698d929830b3bd8b
and update Objective-C, C++, and GObject binding generators to use isReadOnly.

* bindings/scripts/CodeGeneratorCPP.pm:
(GenerateHeader):
(GenerateImplementation):
* bindings/scripts/CodeGeneratorGObject.pm:
(GetWriteableProperties):
(GenerateProperty):
(GenerateFunctions):
* bindings/scripts/CodeGeneratorJS.pm:
(IsReadonly):
* bindings/scripts/CodeGeneratorObjC.pm:
(GenerateHeader):
(GenerateImplementation):
* bindings/scripts/IDLParser.pm:
(parseAttributeRest):
(parseExceptionField):
(parseAttributeRestOld):

Tools:

Use newly added isReadOnly attribute.

* WebKitTestRunner/InjectedBundle/Bindings/CodeGeneratorTestRunner.pm:
(_generateHeaderFile):
(_generateImplementationFile):
(_staticValuesGetterImplementation):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@149679 268f45cc-cd09-0410-ab3c-d52691b4dbfc