Kernel: Crash while shutting down with a stopped process

[implicitfield]

Seems like thread and process states aren't getting desynchronized when stopping (not sure why the VERIFY would expect that tbh). This happens quite easily, just:

1. start any process (e.g. cat)
2. ^Z
3. poweroff

...and you'll hit this assertion during the shutdown process:

serenity/Kernel/Tasks/Thread.cpp

Lines 366 to 370 in 5cd22bb

	if (is_stopped()) {
	// If we were stopped, we need to briefly resume so that
	// the kernel stacks can clean up. We won't ever return back
	// to user mode, though
	VERIFY(!process().is_stopped());