freedreno/a2xx: silence warning about missing DEPTH32X

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
util/primconvert: pass index bias through

The index_bias (aka base_vertex) applies to the downstream draw just as
much, since the actual index values are never modified.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
freedreno/a3xx: handle index_bias (i.e. base_vertex)

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
WIP freedreno/a3xx: avoid out-of-bounds accesses when max_index too big

max_index comes from the user (or is entirely absent), so we have to
compute a tighter bound on it. Use the bo size (+ stride) to determine
the maximum number of vertices.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>