[Mesa-dev] radeonsi ARB_clear_texture support

[Edward O'Callaghan]

The following patches make steps towards getting ARB_clear_texture
support working on radeonsi. There is still some outstanding work
to be done before we may toggle on the PIPE and check it off as
done.

The following is thus preliminary refactoring to set the stage
for further work without the churn. I also would like to seek
some feedback at this stage on possibly new ideas on why the
ARB_clear_texture-float test could be failing from piglit.
I've spent quite some time on this now without much success
and so throwing some ideas around could be useful for this
to progress.