[m-dev.] for review: bugfix for unused_args in accurate gc

[Simon Taylor]

> compiler/unused_args.m:
> 	When compiling for accurate GC, the typeinfo arguments cannot
> 	be eliminated unless all data of that type is eliminated.
> 	So we make sure the typeinfo variables depend upon any variables
> 	who have corresponding type parameters. They are then considered
> 	"used" by the analysis if anything they depend upon is "used".

That looks fine Tyson.

Simon.