Here's a patch just for Modules/sysmodule.c (and related files), based on Georg's patch, updated to apply against current default, including fixes thanks to Serhiy's review.

Despite Serhiy's suggestions, I've not used parameter groups, due to Larry's statement of his dislike of this (ab)use of the feature.

I've left an alias of the form "args as args_value:" since the latest clinic.py doesn't automatically alias "args" (causing a compile error).

At Serhiy's suggestion, I've also converted sys.callstats. I couldn't find any tests for it, so someone should definitely review this conversion!

All tests pass on my OSX 10.10.