[PATCH 5 of 6 mergedriver] merge.mergestate: add a generator for driver-resolved files

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1444860067 25200
#      Wed Oct 14 15:01:07 2015 -0700
# Node ID 9f41136f7fa1528e16445da843b63945fbe27857
# Parent  409747fc77917ef155c9c5d5c197056e40f63da9
merge.mergestate: add a generator for driver-resolved files

Just like for unresolved files above, we need to be able to tell what files are
driver-resolved.

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -329,6 +329,13 @@ class mergestate(object):
             if entry[0] == 'u':
                 yield f
 
+    def driverresolved(self):
+        """Obtain the paths of driver-resolved files."""
+
+        for f, entry in self._state.items():
+            if entry[0] == 'd':
+                yield f
+
     def _resolve(self, preresolve, dfile, wctx, labels=None):
         """rerun merge process for file path `dfile`"""
         if self[dfile] in 'rd':