* path.cc: Translate scan states from defines to enums.

* path.cc: Translate scan states from defines to enums.
(suffix_scan): Rename state to nextstate for clarity.
(lnk_match): Change to allow multiple states to indicate that a .lnk has been
matched.
(suffix_scan::has): Eliminate a goto.  Handle .lnk as a special case, since a
.lnk may also need to be tacked on the end of a .lnk.
(suffix_scan::next): Don't increment next state.  Set it specifically.
Recognize new .lnk states.