Basic block infrastructure after dbr pass

[Jim Wilson]

Boris Boesler wrote:
>  The following code generators use FOR_EACH_BB[_REVERSE] in the target 
> machine dependent reorg pass:
>     - bfin
>     - frv
>     - ia64
>     - mt
>     - s390

The very first thing that ia64_reorg does is
   compute_bb_for_insn ();

Just taking a quick look, I don't see any  bb usage in the s390 port, 
and I see bfin and frv calls compute_bb_for_insns also.  mt isn't using 
the full bb->insn mapping table, it is only using the bb tail, so it is 
probably not broken.

I think most basic block info should still be there at the end, it is 
the bb->insn mapping table that disappears.  See the code for 
pass_free_cfg.  This table can be recomputed if you need it.

Jim