agx: Convert and clamp array indices in NIR

..Rather than at backend IR translation time. This is considerably
simpler because we can use the txs lowering instead of special casing
array sizes. Unfortunately it generates worse code, but that gap should
close once nir_opt_preamble is wired in.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18652>

src/asahi/compiler/agx_compiler.h

@@ -741,6 +741,7 @@ void agx_compute_liveness(agx_context *ctx);
 void agx_liveness_ins_update(BITSET_WORD *live, agx_instr *I);
 
 bool agx_lower_resinfo(nir_shader *s);
+bool agx_nir_lower_array_texture(nir_shader *s);
 
 #ifdef __cplusplus
 } /* extern C */