- http://bugs.webkit.org/show_bug.cgi?id=15826
          optimize opcode loop and case insensitive ASCII compares for a 30% speedup

        SunSpider says it's 2.6% faster overall, 32.5% in the regular expression tests.

        * pcre/pcre_internal.h: Added OP_ASCII_CHAR and OP_ASCII_LETTER_NC.

        * pcre/pcre_compile.c:
        (find_fixedlength): Added cases for OP_ASCII_CHAR and OP_ASCII_LETTER_NC. Also
        added OP_NOT since there was no reason it should not be in here.
        (could_be_empty_branch): Ditto.
        (compile_branch): Streamlined all the single-character cases; there was a bit of
        duplicate code. Added cases for OP_ASCII_CHAR and OP_ASCII_LETTER_NC as needed.
        But in particular, compile to those opcodes when the single character match is
        ASCII.
        (find_firstassertedchar): Added cases for OP_ASCII_CHAR and OP_ASCII_LETTER_NC.

        * pcre/pcre_exec.c: (match): Removed the "min", "minimize", and "op" fields from
        the matchframe, after I discovered that none of them needed to be saved and restored
        across recursive match calls. Also eliminated the ignored result field from the
        matchframe, since I discovered that rrc ("recursive result code") was already the
        exact same thing. Moved the handling of opcodes higher than OP_BRA into the default
        statement of the switch instead of doing them before the switch. This removes a
        branch from each iteration of the opcode interpreter, just as removal of "op"
        removed at least one store from each iteration. Last, but not least, add the
        OP_ASCII_CHAR and OP_ASCII_LETTER_NC functions. Neither can ever match a
        surrogate pair and the letter case can be handled efficiently.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@27422 268f45cc-cd09-0410-ab3c-d52691b4dbfc