intel,ir3: Re-enable nir_opt_copy_prop_vars

Now that it's rewritten for deref instructions, we can turn it back on.

Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/gallium/drivers/freedreno/ir3/ir3_nir.c

@@ -92,7 +92,7 @@ ir3_optimize_loop(nir_shader *s)
 		progress = false;
 
 		OPT_V(s, nir_lower_vars_to_ssa);
-		/* progress |= OPT(s, nir_opt_copy_prop_vars); */
+		progress |= OPT(s, nir_opt_copy_prop_vars);
 		progress |= OPT(s, nir_lower_alu_to_scalar);
 		progress |= OPT(s, nir_lower_phis_to_scalar);
 

src/intel/compiler/brw_nir.c

@@ -543,7 +543,7 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
    do {
       progress = false;
       OPT(nir_lower_vars_to_ssa);
-      /* OPT(nir_opt_copy_prop_vars); */
+      OPT(nir_opt_copy_prop_vars);
 
       if (is_scalar) {
          OPT(nir_lower_alu_to_scalar);