0.pre7.86.flaky7.20:

0.pre7.86.flaky7.20:
	(This version bootstrapped successfully from 0.6.13, passed
		regression tests, served as its own bootstrap host,
		and passed regression tests again. But it still has
		debugger/signal/whatever problems, so that A doesn't
		work from the debugger prompt, and after it fails,
		(SB-EXT:QUIT) doesn't work either.)
	The failure in clocc-ansi-test was in the find-the-home-lambda
		part of the new code which updates LAMBDA-REFERS-TO-VAR
		in IR1 translation of SETQ. We try to find the home
		lambda by looking backwards through continuations,
		but in the (SETQ X 3) form in
		      (SETQ X 2)
		      (RETURN-FROM STOP)
		      (SETQ X 3))
		it doesn't work to look backwards. (To make a point
		which eluded me for a while, this isn't a bug in the
		way that continuations are set up, it's because the
		(SETQ X 3) form is orphaned by the way that control
		always jumps out through RETURN-FROM, so that the
		(SETQ X 3) form effectively has no home lambda.) So...
	...redid CONTINUATION-HOME-LAMBDA in terms of
		CONTINUATION-HOME-LAMBDA-OR-NULL, and BLOCK-HOME-LAMBDA
		in terms of BLOCK-HOME-LAMBDA-OR-NULL
	...made the update-LAMBDA-REFERS-TO-VAR code accept a NIL
		answer from CONTINUATION-HOME-LAMBDA-OR-NULL