nir: Don't lower TCS outputs to temporaries.

We'd like to shadow these when possible, but the current code doesn't
work properly for TCS outputs.  For now, disable it.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>

src/glsl/nir/nir_lower_outputs_to_temporaries.c

@@ -78,6 +78,9 @@ nir_lower_outputs_to_temporaries(nir_shader *shader)
 {
    struct lower_outputs_state state;
 
+   if (shader->stage == MESA_SHADER_TESS_CTRL)
+      return;
+
    state.shader = shader;
    exec_list_move_nodes_to(&shader->outputs, &state.old_outputs);