3.3 PATCH: Handle mips gas 2.13 -mdebug switch

[Eric Christopher]

> mips-sgi-irix6*o32 configuration.  The problem is that the assembler
> requires the new -mdebug switch to correctly assemble input files with
> stabs-in-mdebug or ecoff-in-mdebug debugging information.
> 
> The following patch fixes a large part of the problem:
> 
> * It detects if the assembler used supports the -mdebug switch at all.
> 
> * If so, it defines a new mdebug_asm_spec to handle the core of the
>   problem:
> 
> ** If the default debugging format is DWARF-2, only gcc invokations with
>    -gstabs* or -gcoff* need to pass -mdebug on to gas.
> 
> ** If the default debugging format is Stabs or ECOFF, -mdebug must be
>    always passed unless -gdwarf-2* is specified.
> 

Couple of things:

0) I was just working on this myself. If you require #1 it's much easier
;)

1) I wish there was a way to require certain versions of gas with
certain versions of gcc.

2) The configure part of this patch is missing :)

3) I'm trying to get rid of SDB_DEBUGGING, in a patch I'll be committing
shortly I'm moving everything but mips-ecoff, mips-sni, and irix5. I'm
not sure about the o32 irix6.

4) The patch in general looks ok to me after these comments. You'll need
more approval than me though.

-eric

-- 
I will not grease the monkey bars