[PATCH 4 of 4] py3: convert os.readlink() path to native strings

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1537924572 14400
#      Tue Sep 25 21:16:12 2018 -0400
# Node ID d7aa84fbb3da463c68190aa746cbc6af40c6b8bc
# Parent  549bc25529a2d8d1c67736110c90491cc1eafc76
py3: convert os.readlink() path to native strings

Windows insisted that it needs to be str.  I skipped the stuff that's obviously
posix only, and left `tests/f` and `run-tests.py` alone for now.

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -1841,7 +1841,7 @@ def makelock(info, pathname):
 
 def readlock(pathname):
     try:
-        return os.readlink(pathname)
+        return os.readlink(pycompat.fsdecode(pathname))
     except OSError as why:
         if why.errno not in (errno.EINVAL, errno.ENOSYS):
             raise
diff --git a/mercurial/vfs.py b/mercurial/vfs.py
--- a/mercurial/vfs.py
+++ b/mercurial/vfs.py
@@ -206,7 +206,7 @@ class abstractvfs(object):
         return util.rename(srcpath, dstpath)
 
     def readlink(self, path):
-        return os.readlink(self.join(path))
+        return os.readlink(pycompat.fsdecode(self.join(path)))
 
     def removedirs(self, path=None):
         """Remove a leaf directory and all empty intermediate ones