[RFC][PATCH 0/6] clean up class switching

[Peter Zijlstra]

Hi!

Recent changes (scx and especially sched_delayed) made bit of a mess of
sched_class changes.

The first patch fixes an scx bug (some day I'll remember scx), while the rest
cleans up the whole sched_class::switch*()-eroo stuff.

Patches are very lightly tested (as in, the test box boots).