Cache C string identifiers by address, not value, assuming that C strings can only
        be literals.

        1% speedup on Acid3 test 26.

        * kjs/identifier.cpp:
        (KJS::literalIdentifierTable):
        (KJS::Identifier::add):
        Added a new table to cache UString::Reps created from C strings by address. Elements are
        never removed from this cache, as only predefined identifiers can get there.

        * kjs/identifier.h:
        (KJS::Identifier::Identifier): Added a warning.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31319 268f45cc-cd09-0410-ab3c-d52691b4dbfc