gallivm/nir: add support for indirect image loading

This adds support for indirect image loading, image stores
can cause images with different formats to be stored to,
so this operates like the texture code now.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3778>
2 files changed