Reviewed by Maciej Stachowiak.

        Lexer needs to provide Identifier for reserved words
        https://bugs.webkit.org/show_bug.cgi?id=62086

        Alas it is necessary to provide an Identifier reference for keywords
        so that we can do the right thing when they're used in object literals.
        We now keep Identifiers for all reserved words in the CommonIdentifiers
        structure so that we can access them without a hash lookup.

        * KeywordLookupGenerator.py:
        * parser/Lexer.cpp:
        (JSC::Lexer::parseIdentifier):
        * parser/Lexer.h:
        * runtime/CommonIdentifiers.cpp:
        (JSC::CommonIdentifiers::CommonIdentifiers):
        * runtime/CommonIdentifiers.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@88094 268f45cc-cd09-0410-ab3c-d52691b4dbfc