[RFA/RFC] fix problems with unwinder on mips-irix

[Andrew Cagney]

Joel,

> 2004-07-22  Joel Brobecker  <brobecker@gnat.com>
> 
>         * mips-tdep.c (mips_mdebug_frame_cache): Minor reformatting.
>         (set_saved_reg_info): New function.
>         (mips32_heuristic_proc_desc): Compute the procedure descriptor
>         PROC_REG_OFFSET.
> 

It's time to cut our losses and split the mdebug and heuristic cases. 
Lets work through this change after I've done that.

In the mean time, can I encourage you to look at the s390 and it's 
stub-unwinder - the MIPS desperatly needs one of these (and it is 
something that can be wipped up in isolation).  To see where its needed 
do a STEPI into shlib trampoline code.

Andrew