py3: do not convert rust module/attribute names to bytes

policy.import*() functions expect system strings.

mercurial/match.py

@@ -25,7 +25,7 b' from .utils import ('
     stringutil,
 )
 
-rustmod = policy.importrust('filepatterns')
+rustmod = policy.importrust(r'filepatterns')
 
 allpatternkinds = ('re', 'glob', 'path', 'relglob', 'relpath', 'relre',
                    'rootglob',

mercurial/setdiscovery.py

@@ -270,8 +270,8 b' class partialdiscovery(object):'
                 sample.update(takefrom[:more])
         return sample
 
-partialdiscovery = policy.importrust('discovery',
-                                     member='PartialDiscovery',
+partialdiscovery = policy.importrust(r'discovery',
+                                     member=r'PartialDiscovery',
                                      default=partialdiscovery)
 
 def findcommonheads(ui, local, remote,

mercurial/util.py

@@ -53,7 +53,7 b' from .utils import ('
     stringutil,
 )
 
-rustdirs = policy.importrust('dirstate', 'Dirs')
+rustdirs = policy.importrust(r'dirstate', r'Dirs')
 
 base85 = policy.importmod(r'base85')
 osutil = policy.importmod(r'osutil')