fileset: suppress EACCES while reading arbitrary paths via filectx API

On Windows, EACCES is raised in place of EISDIR. This patch simply adds
EACCES to the list of errors to be ignored since I think it's okay for
filesets to treat inaccessible working-copy files as not existing.

mercurial/fileset.py

@@ -592,7 +592,9 class matchctx(object):
                 try:
                     return predfn(fctx)
                 except (IOError, OSError) as e:
-                    if e.errno in (errno.ENOENT, errno.ENOTDIR, errno.EISDIR):
+                    # open()-ing a directory fails with EACCES on Windows
+                    if e.errno in (errno.ENOENT, errno.EACCES, errno.ENOTDIR,
+                                   errno.EISDIR):
                         return False
                     raise
         else: