util, posix: eliminate encodinglower and encodingupper

2ebe3d0ce91d claims this was needed "to avoid cyclic dependency", but there is
no cyclic dependency.

windows.py already imports encoding, posix.py can import it too, so we can
simply use encoding.upper in windows.py and in posix.py.

(this is a partial backout of 2ebe3d0ce91d)

mercurial/posix.py

@@ -6,6 +6,7 b''
 # GNU General Public License version 2 or any later version.
 
 from i18n import _
+import encoding
 import os, sys, errno, stat, getpass, pwd, grp, tempfile, unicodedata
 
 posixfile = open
@@ -164,9 +165,6 b' def samedevice(fpath1, fpath2):'
     st2 = os.lstat(fpath2)
     return st1.st_dev == st2.st_dev
 
-encodinglower = None
-encodingupper = None
-
 # os.path.normcase is a no-op, which doesn't help us on non-native filesystems
 def normcase(path):
     return path.lower()
@@ -255,7 +253,7 b" if sys.platform == 'cygwin':"
         pathlen = len(path)
         if (pathlen == 0) or (path[0] != os.sep):
             # treat as relative
-            return encodingupper(path)
+            return encoding.upper(path)
 
         # to preserve case of mountpoint part
         for mp in cygwinmountpoints:
@@ -266,9 +264,9 b" if sys.platform == 'cygwin':"
             if mplen == pathlen: # mount point itself
                 return mp
             if path[mplen] == os.sep:
-                return mp + encodingupper(path[mplen:])
+                return mp + encoding.upper(path[mplen:])
 
-        return encodingupper(path)
+        return encoding.upper(path)
 
     # Cygwin translates native ACLs to POSIX permissions,
     # but these translations are not supported by native

mercurial/util.py

@@ -24,9 +24,6 b" if os.name == 'nt':"
 else:
     import posix as platform
 
-platform.encodinglower = encoding.lower
-platform.encodingupper = encoding.upper
-
 cachestat = platform.cachestat
 checkexec = platform.checkexec
 checklink = platform.checklink

mercurial/windows.py

@@ -130,11 +130,8 b' def localpath(path):'
 def normpath(path):
     return pconvert(os.path.normpath(path))
 
-encodinglower = None
-encodingupper = None
-
 def normcase(path):
-    return encodingupper(path)
+    return encoding.upper(path)
 
 def realpath(path):
     '''