changelog: inline revlog.__contains__ in case it is used in hot loop

Currently __contains__ is called only by "rev()" revset, but "x in cl" is a
function that is likely to be used in hot loop. revlog.__contains__ is simple
enough to duplicate to changelog, so just inline it.

mercurial/changelog.py

@@ -145,7 +145,7 b' class changelog(revlog.revlog):'
 
     def __contains__(self, rev):
         """filtered version of revlog.__contains__"""
-        return (revlog.revlog.__contains__(self, rev)
+        return (0 <= rev < len(self)
                 and rev not in self.filteredrevs)
 
     def __iter__(self):