check-code: ban use of bare xrange()

We want everyone to use pycompat.xrange().

Differential Revision: https://phab.mercurial-scm.org/D4033

contrib/check-code.py

@@ -511,6 +511,7 b' py3pats = ['
     (r'getopt\.getopt', "use pycompat.getoptb instead (py3)"),
     (r'os\.getenv', "use encoding.environ.get instead"),
     (r'os\.setenv', "modifying the environ dict is not preferred"),
+    (r'(?<!pycompat\.)xrange', "use pycompat.xrange instead (py3)"),
   ],
   # warnings
   [],