0.7.13.5

0.7.13.5
	Committed patch for gencgc refactoring based on work done
	on threads branch.

	... to make header file management a lot simpler, and allow
	the use of interesting typedefs in genesis :C-TYPE slot
	options, we split runtime.h into lots of smaller files that
	can be (semi-)independently included.

	... all GC and GCish functions now have the same interface,
	so no need for (eq *internal-gc* #'collect-garbage) test in
	SUB-GC

	... current_region_end_addr and current_region_free_pointer
	go away, eliminating potential for weird bugs when they're
	not synchronized properly.  Yay OAOO

	... disabled (actually, removed) inline allocation, as it
	depended on old current_region_* (see above) and appears
	to make not a lot of actual difference to run times anyway

	pseudo-atomic support is now always compiled in.  I can see
	no good reason for not having it

	... much code in alloc() collapsed.  Also alloc() no longer
	attempts to drop its PA and do a collection in the middle of
	allocation - instead it uses the existing maybe_gc flag to
	indicate that collection should happen when the allocation is
	done.  Possibly this has bad effects when trying to allocate
	an object bigger than available dynamic space, but that would
	fit if a GC were done first.  Given the (complete lack of)
	error handling for out-of-memory conditions in this and all
	previous SBCL versions, it would be a foolish programmer who
	was depending on this anyway, though.