Code Generated by Macros

[greek@DEC-HUDSON]

We found that the following "macros" generated loops that hid a
surrounding NIL block:

	CCASE
	CTYPECASE
	DO-SYMBOLS et al
	lots of compiler transformations (e.g., that turned a map
		into a loop)

Also, of course, plenty of macros written by users can inadvertently
cause the problem.

The simplest way around is to only generate TAGBODYs.  Even PROG
establishes a NIL block.

- Paul