radv: Lower input attachments in NIR.

v2 (Connor)
- Fix warning in release mode using MAYBE_UNUSED

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/vulkan/radv_shader.c

@@ -334,6 +334,9 @@ radv_shader_compile_to_nir(struct radv_device *device,
 		NIR_PASS_V(nir, nir_split_var_copies);
 		NIR_PASS_V(nir, nir_split_per_member_structs);
 
+		if (nir->info.stage == MESA_SHADER_FRAGMENT)
+			NIR_PASS_V(nir, nir_lower_input_attachments);
+
 		NIR_PASS_V(nir, nir_remove_dead_variables,
 		           nir_var_shader_in | nir_var_shader_out | nir_var_system_value);