pan/bi: Handle non-2D arrays

pan/bi: Handle non-2D arrays

Handle arrays generically by using the last component of the coordinate source
as the array index. That works for both 2D arrays and cube arrays, fixing cube
arrays. Cube arrays were already handled correctly in core Panfrost code.

This code path is not tested in dEQP-GLES31 without exposing OES_cube_map_array,
which depends on OES_geometry_shader, which we don't have. Yet we do expose
PIPE_CAP_CUBE_ARRAY, so ARB_cube_map_array is exposed.

Disabling PIPE_CAP_CUBE_ARRAY would be an easy band-aid fix, but it's easy
enough to handle correctly.

dEQP-GLES31 passes with a hack enabling OES_cube_map_array [without geometry
shaders].

Also fixes 1D arrays on Bifrost for the same reasons.

Fixes: 70d6c5675d6 ("pan/bi: Emit TEXC with builder")
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15254>