nir: Treat vec8/16 as select in opt_peephole_select

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4365>

src/compiler/nir/nir_opt_peephole_select.c

@@ -119,6 +119,8 @@ block_check_for_allowed_instrs(nir_block *block, unsigned *count,
          case nir_op_vec2:
          case nir_op_vec3:
          case nir_op_vec4:
+         case nir_op_vec8:
+         case nir_op_vec16:
             movelike = true;
             break;