0.8.13.67:

0.8.13.67:
	Implement modular ASH for non-constant positive shifts
	... make sure that we only apply the transform when we know
		the shift count won't be misinterpreted...
	... and also that we don't do the more expensive non-constant
		shift for constant counts;
	... punt on some of the cleverness for hppa; all other platforms
		should be optimal.
	... one test for something which went wrong in an earlier version.