py3: select input or raw_input by pycompat

py3: select input or raw_input by pycompat

This seems slightly cleaner.

--- a/mercurial/pycompat.py	Wed Aug 16 13:50:11 2017 +0900
+++ b/mercurial/pycompat.py	Wed Aug 16 13:54:24 2017 +0900
@@ -63,6 +63,7 @@
         sysexecutable = os.fsencode(sysexecutable)
     stringio = io.BytesIO
     maplist = lambda *args: list(map(*args))
+    rawinput = input
 
     # TODO: .buffer might not exist if std streams were replaced; we'll need
     # a silly wrapper to make a bytes stream backed by a unicode one.
@@ -312,6 +313,7 @@
     shlexsplit = shlex.split
     stringio = cStringIO.StringIO
     maplist = map
+    rawinput = raw_input
 
 class _pycompatstub(object):
     def __init__(self):

--- a/mercurial/util.py	Wed Aug 16 13:50:11 2017 +0900
+++ b/mercurial/util.py	Wed Aug 16 13:54:24 2017 +0900
@@ -176,10 +176,7 @@
     sin, sout = sys.stdin, sys.stdout
     try:
         sys.stdin, sys.stdout = encoding.strio(fin), encoding.strio(fout)
-        if pycompat.ispy3:
-            return encoding.strtolocal(input(*args, **kwargs))
-        else:
-            return raw_input(*args, **kwargs)
+        return encoding.strtolocal(pycompat.rawinput(*args, **kwargs))
     finally:
         sys.stdin, sys.stdout = sin, sout