"name" and "message" enumerable on *Error.prototype

Reviewed by Sam Weinig.

Source/JavaScriptCore: 

The default value of a NativeErrorPrototype's message
property is "", not the name of the error.

* runtime/NativeErrorConstructor.cpp:
(JSC::NativeErrorConstructor::NativeErrorConstructor):
* runtime/NativeErrorConstructor.h:
(JSC::NativeErrorConstructor::create):
(JSC::NativeErrorConstructor::constructorBody):
* runtime/NativeErrorPrototype.cpp:
(JSC::NativeErrorPrototype::NativeErrorPrototype):
(JSC::NativeErrorPrototype::constructorBody):
* runtime/NativeErrorPrototype.h:
(JSC::NativeErrorPrototype::create):
* runtime/StringPrototype.cpp:
(JSC::StringPrototype::StringPrototype):
* runtime/StringPrototype.h:
(JSC::StringPrototype::create):

LayoutTests: 

* fast/js/exception-properties-expected.txt:
* fast/js/script-tests/exception-properties.js:
    - Add tests for value of RangeError.__proto__.{name|message}



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@93624 268f45cc-cd09-0410-ab3c-d52691b4dbfc