0.6.12.21.flaky2.2:

0.6.12.21.flaky2.2:
	(This version seems not to be flaky any more. I'm just
		checking it in as a halfway step to merging it
		back into the main branch.
	tweaked scavenge() argument handling so that it's easier to see
		what was going on when we look at it with gdb
	deleted unused undocumented DIRECT_SCAV stuff
	deleted unused undocumented SC_NS_GEN_CK stuff
	stopped tests/interface.pure.lisp from generating un-GC-able
		nonsense values when a SYMBOL-FUNCTION is a closure;
		and tried to make it more accurately check for
		undocumented external functions as well