regex.c: Remove the old analyzes functions

regex.c: Remove the old analyzes functions

After testing and checking that the changes brought by the new
consolidated analysis function (which are all cases of improved
optimizations) are indeed safe, remove the old code.

* src/regex-emacs.c (analyze_first_old): Delete function.
(analyze_first): Don't call it any more.
(skip_noops): Delete function.
(mutually_exclusive_aux): Delete function.
(mutually_exclusive_p): Don't call it any more.