[DF] Replace various bitmaps with HARD_REG_SETs

[Jakub Jelinek]

On Sat, Jul 30, 2011 at 07:08:39PM +0200, Jakub Jelinek wrote:
> So, if you really want a target hook to return or fill up a HARD_REG_SET,
> I think it is best to pass void * around if we don't to include tm.h back in
> target hook headers.

An alternative would be to put HARD_REG_SET into a struct just for those
APIs that can't have tm.h included and leave HARD_REG_SET as a type as is.
There would be
struct hard_reg_set_wrapped;
the target hooks would take struct hard_reg_set_wrapped * arguments and
struct hard_reg_set_wrapped would be then defined somewhere to
struct hard_reg_set_wrapped
{
  HARD_REG_SET set;
};
But I really think it is a mistake to change HARD_REG_SET itself, at least
before we are actually there to be able to have a full multi-target cc1 (if
that is a goal).

	Jakub