broadcom/compiler: allow color TLB writes in last instruction

Only Z writes are disallowed.

total instructions in shared programs: 11578449 -> 11577369 (<.01%)
instructions in affected programs: 38132 -> 37052 (-2.83%)
helped: 1080
HURT: 0
Instructions are helped.

total max-temps in shared programs: 2334416 -> 2334395 (<.01%)
max-temps in affected programs: 218 -> 197 (-9.63%)
helped: 21
HURT: 0
Max-temps are helped.

total inst-and-stalls in shared programs: 11607890 -> 11606810 (<.01%)
inst-and-stalls in affected programs: 38265 -> 37185 (-2.82%)
helped: 1080
HURT: 0
Inst-and-stalls are helped.

total nops in shared programs: 338316 -> 337236 (-0.32%)
nops in affected programs: 2625 -> 1545 (-41.14%)
helped: 1080
HURT: 0
Nops are helped.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13964>

src/broadcom/compiler/v3d_compiler.h

@@ -169,6 +169,9 @@ struct qinst {
          * otherwise.
          */
         int uniform;
+
+        /* If this is a a TLB Z write */
+        bool is_tlb_z_write;
 };
 
 enum quniform_contents {