[glibc] powerpc: Update acosf ulps

[Paul Zimmermann]

       Hi Florian,

> >> Isn't the new acosf implementation supposed to be correctly rounded?
> >
> > yes, but due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57245,
> > the new implementation might be miscompiled by gcc < 12.
> >
> > I strongly recommend updating ulps only with gcc >= 12.
> 
> Oh, I wasn't aware of that.  I think I pushed quite a few ulps updates
> that were caused by this bug. 8-(
> 
> I'll ask if we can get our build of GCC 11 fixed.  Maybe we should raise
> the minimum version to GCC 12 for glibc builds if earlier versions
> cannot build libm correctly.

first please check everything is ok with GCC 12 on the machines where you
got failures or ulp updates.

Paul