match: remove ispartial()

The function was added in d1d69ca78883 (match: add match.ispartial(),
2015-05-15) for use by narrowhg, but narrowhg never ended up needing
it.

mercurial/localrepo.py

@@ -1575,7 +1575,7 b' class localrepository(object):'
             wctx = self[None]
             merge = len(wctx.parents()) > 1
 
-            if not force and merge and match.ispartial():
+            if not force and merge and not match.always():
                 raise error.Abort(_('cannot partially commit a merge '
                                    '(do not specify files or patterns)'))
 

mercurial/match.py

@@ -281,14 +281,6 b' class match(object):'
         - optimization might be possible and necessary.'''
         return self._always
 
-    def ispartial(self):
-        '''True if the matcher won't always match.
-
-        Although it's just the inverse of _always in this implementation,
-        an extension such as narrowhg might make it return something
-        slightly different.'''
-        return not self._always
-
     def isexact(self):
         return self.matchfn == self.exact