nvk: Handle missing gl_PointSize in the last geometry stage

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27795>

src/nouveau/vulkan/nvk_cmd_draw.c

@@ -255,14 +255,8 @@ nvk_push_draw_state_init(struct nvk_device *dev, struct nv_push *p)
       .output7 = OUTPUT7_FALSE,
    });
 
-   /* vulkan allows setting point sizes only within shaders */
-   P_IMMD(p, NV9097, SET_ATTRIBUTE_POINT_SIZE, {
-      .enable  = ENABLE_TRUE,
-      .slot    = 0,
-   });
    P_IMMD(p, NV9097, SET_POINT_SIZE, fui(1.0));
 
-
    /* From vulkan spec's point rasterization:
     * "Point rasterization produces a fragment for each fragment area group of
     * framebuffer pixels with one or more sample points that intersect a region

src/nouveau/vulkan/nvk_graphics_pipeline.c

@@ -417,6 +417,11 @@ nvk_graphics_pipeline_create(struct nvk_device *dev,
                  CONTROL_V_SELECTS_LAYER,
    });
 
+   P_IMMD(p, NV9097, SET_ATTRIBUTE_POINT_SIZE, {
+      .enable  = last_geom->info.vtg.writes_point_size,
+      .slot    = 0,
+   });
+
    emit_pipeline_xfb_state(&push, &last_geom->info.vtg.xfb);
 
    emit_pipeline_ct_write_state(&push, state.cb, state.rp);