localrepo: changed revs to use spanset instead of baseset

Performance benchmarking:

$ time hg log -qf -l1
...

real  0m1.420s
user  0m1.249s
sys 0m0.167s

$ time ~/local/hg/hg log -qf -l1
...

real  0m0.719s
user  0m0.614s
sys 0m0.103s

mercurial/localrepo.py

@@ -428,7 +428,7 b' class localrepository(object):'
         '''Return a list of revisions matching the given revset'''
         expr = revset.formatspec(expr, *args)
         m = revset.match(None, expr)
-        return revset.baseset([r for r in m(self, revset.baseset(self))])
+        return m(self, revset.spanset(self))
 
     def set(self, expr, *args):
         '''