branchcache: rename itervalues() to iterheads() The itervalues() exists because branchcache() had a dict interface. Since it no longer has a dict interface, it makes sense to have better function names. If a person does not understand how branchcache stores info, it will be hard for them to guess what itervalues() does. Differential Revision: https://phab.mercurial-scm.org/D6152

--- a/mercurial/bundle2.py	Mon Mar 18 18:59:38 2019 +0300
+++ b/mercurial/bundle2.py	Mon Mar 18 19:01:29 2019 +0300
@@ -1980,7 +1980,7 @@
         op.gettransaction()
 
     currentheads = set()
-    for ls in op.repo.branchmap().itervalues():
+    for ls in op.repo.branchmap().iterheads():
         currentheads.update(ls)
 
     for h in heads: