Important workaround for brw_meta_fast_clear segfaults on some Intel GC

[Enrico Tagliavini]

Hi,

this bug generated quite some fuss already in the internet, so
probably you are aware of it. Since it is quite important I would like
to bring it to your attention if it has been not. The bug is
https://bugzilla.redhat.com/show_bug.cgi?id=1259443

This heavily (and mainly) affect desktops installation, especially KDE
spins, but also multimedia applications.

Since user experience is heavily affected (to the point I just
recompiled mesa with the named workaround to get my work desktop
usable again) I thought it was a good idea to point it out on the
mailing list to hopefully get a workaround in quickly.

Thank you for your help.
Best regards

Enrico