[MIPS, committed] Revert some Octeon BADDU patches

[Eric Botcazou]

> This patch just reverts some changes I'd made to the BADDU patterns
> for the infamous (truncate:QI (plus:SI ...)) -> (plus:QI ...)
> simplification. That simplification was limited to CISCy targets for PR
> 58295.
> 
> Tested on mips64-linux-gnu and applied.  It fixes the octeon-baddu-1.c
> failures.

You presumably need to apply it to the 4.8 branch as well.

-- 
Eric Botcazou