freedreno/ir3: build binning variant at same time as draw variant

freedreno/ir3: build binning variant at same time as draw variant

For shader-cache, we are going to want to serialize them together.
Which is awkward if the two related variants are not compiled together.

This also decouples allocation and compile, which will simplify adding
shader-cache (which still needs to allocate, but can skip compile).

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5372>