Reviewed by Geoffrey Garen.

        Improve keyword lookup
        https://bugs.webkit.org/show_bug.cgi?id=61913

        Rather than doing multiple hash lookups as we currently
        do when trying to identify keywords we now use an
        automatically generated decision tree (essentially it's
        a hard coded patricia trie).  We still use the regular
        lookup table for the last few characters of an input as
        this allows us to completely skip all bounds checks.

        * CMakeLists.txt:
        * DerivedSources.make:
        * DerivedSources.pro:
        * GNUmakefile.am:
        * JavaScriptCore.gyp/JavaScriptCore.gyp:
        * JavaScriptCore.xcodeproj/project.pbxproj:
        * KeywordLookupGenerator.py: Added.
        * make-generated-sources.sh:
        * parser/Lexer.cpp:
        (JSC::Lexer::internalShift):
        (JSC::Lexer::shift):
        (JSC::Lexer::parseIdentifier):
        * parser/Lexer.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@88076 268f45cc-cd09-0410-ab3c-d52691b4dbfc