Show cfunc frames in rb_profile_frames()
rb_profile_frames(), which is the backend of stackprof, shows only ruby frames, so sometimes it is difficult to find a bottleneck in an application.
This will be gradually solved by "rubifying" all builtin methods (#16254), but I guess it will take a few years at least. So, how about showing cfunc frames in the profiled result that returns
Here is a patch and an example stackprof result: