0.8.9.46:

0.8.9.46:
	deKLUDGE the solution for PACK-BEFORE-GC-HOOK
	... well, not completely.  PACK remains non-reentrant and
		non-threadsafe, but at least now global data structures
		don't grow without bounds;
	... mostly whitespace changes, but clear the PACK structures
		after every call, not once per GC cycle.  Marginally
		less efficient, I fear :-(
	... while we're at it, fix analogously VOP-TN-REFS, and while
		we're at it, document that a special is a bit of an
		odd way to implement a (non-reentrant non-threadsafe)
		closure.
	... only one BEFORE-GC-HOOK left.