[PATCH 5 of 9] py3: replace dict.iterkeys() with iter(dict)

[Pulkit Goyal]

# HG changeset patch
# User Pulkit Goyal <7895pulkit at gmail.com>
# Date 1497557807 -19800
#      Fri Jun 16 01:46:47 2017 +0530
# Node ID 8c2bdaf9a1901676753ed57df5a99299ded8fa08
# Parent  bdab6e36523f1e547f1753c67d84b3149fea59fe
py3: replace dict.iterkeys() with iter(dict)

dict.iterkeys() does not exists on Python 3.

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -838,7 +838,7 @@
         for copykey, copyvalue in copy.iteritems():
             if copyvalue in relevantfiles:
                 relevantfiles.add(copykey)
-        for movedirkey in movewithdir.iterkeys():
+        for movedirkey in iter(movewithdir):
             relevantfiles.add(movedirkey)
         filesmatcher = scmutil.matchfiles(repo, relevantfiles)
         matcher = matchmod.intersectmatchers(matcher, filesmatcher)