mesa/st: set lower_point_size for tes/gs during program update

these may not reach the other callsite in st_precompile_shader_variant(),
so we need to ensure that we get psiz if we need it

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5885>

src/mesa/state_tracker/st_atom_shader.c

@@ -295,6 +295,10 @@ st_update_common_program(struct st_context *st, struct gl_program *prog,
       if (st->lower_ucp && st_user_clip_planes_enabled(st->ctx) &&
           pipe_shader == PIPE_SHADER_GEOMETRY)
          key.lower_ucp = st->ctx->Transform.ClipPlanesEnabled;
+
+      key.lower_point_size = st->lower_point_size &&
+                             !st_point_size_per_vertex(st->ctx);
+
    }
 
    simple_mtx_lock(&st->ctx->Shared->Mutex);