[PATCH v2] GAS/MIPS: Add `-mfix-r5900' option for the R5900 short loop errata

[Fredrik Noring]

Thank you for your review, Maciej!

>  Please prepare a suitable ChangeLog entry.  I have missed its absence in 
> the initial review somehow (sorry about that), but since we need another 
> iteration anyway, please include it alongside.

Done!

> However please set `mips_fix_r5900' 
> appropriately in `mips_after_parse_args' instead, i.e.:
> 
>   if (!mips_fix_r5900_explicit)
>     mips_fix_r5900 = file_mips_opts.arch == CPU_R5900;
> 
> so that it's the only setting referred in determination as to whether to 
> enable the workaround.

Done!

> This will affect temporary `.set arch=' overrides, 
> but I think they are not supposed to override the global `-mfix-r5900' 
> setting, whether specified or inferred.

Losing -mfix-r5900 inadvertently is fatal to the R5900 and will likely
cause corruption and any other imaginable error, so that must not happen.
This is also the main motivation to implement a warning for unfixable
cases involving for example the noreorder directive.

>  This is otherwise OK, so please resubmit with just this issue addressed.

Great, will post v3 soon!

Fredrik