zink: skip implicit feedback loop layout changes if feedback loop not present

if a resource is bound as both a framebuffer attachment and a sampler but
isn't actually used as a sampler, it's just a framebuffer attachment, and it
should retain its layout as a framebuffer attachment without any barriers

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20674>

src/gallium/drivers/zink/ci/traces-zink-restricted.yml

@@ -44,7 +44,6 @@ traces:
       label: [skip, flakes]
       checksum: 826f966a52bc956644bf41562aa9c686
       text: |-
-        'WARNING: Incorrect rendering will happen because the Vulkan device doesn't support the 'EXT_attachment_feedback_loop_layout' feature.'
         This trace is flaky on freedreno too.
   SirYouAreBeingHunted/sir-f750-v2.trace:
     gl-zink-anv-tgl:

src/gallium/drivers/zink/zink_draw.cpp

@@ -280,11 +280,11 @@ draw(struct zink_context *ctx,
    }
 }
 
-static void
+static bool
 add_implicit_color_feedback_loop(struct zink_context *ctx, struct zink_resource *res)
 {
    if (!res->fb_bind_count || !res->sampler_bind_count[0] || ctx->feedback_loops & res->fb_binds)
-      return;
+      return false;
    bool is_feedback = false;
    /* avoid false positives when a texture is bound but not used */
    u_foreach_bit(vkstage, res->gfx_barrier) {
@@ -297,7 +297,7 @@ add_implicit_color_feedback_loop(struct zink_context *ctx, struct zink_resource
          is_feedback = true;
    }
    if (!is_feedback)
-      return;
+      return false;
    /* new feedback loop detected */
    if (res->aspect == VK_IMAGE_ASPECT_COLOR_BIT) {
       if (!ctx->gfx_pipeline_state.feedback_loop)
@@ -316,6 +316,7 @@ add_implicit_color_feedback_loop(struct zink_context *ctx, struct zink_resource
       else
          ctx->dynamic_fb.attachments[idx].imageLayout = VK_IMAGE_LAYOUT_GENERAL;
    }
+   return true;
 }
 
 static void
@@ -334,10 +335,10 @@ update_barriers(struct zink_context *ctx, bool is_compute,
          if (res->base.b.target == PIPE_BUFFER)
             zink_screen(ctx->base.screen)->buffer_barrier(ctx, res, res->barrier_access[is_compute], pipeline);
          else {
+            bool is_feedback = is_compute ? false : add_implicit_color_feedback_loop(ctx, res);
             VkImageLayout layout = zink_descriptor_util_image_layout_eval(ctx, res, is_compute);
-            if (!is_compute)
-               add_implicit_color_feedback_loop(ctx, res);
-            if (layout != res->layout)
+            /* GENERAL is only used for feedback loops and storage image binds */
+            if (is_feedback || layout != VK_IMAGE_LAYOUT_GENERAL || res->image_bind_count[is_compute])
                zink_screen(ctx->base.screen)->image_barrier(ctx, res, layout, res->barrier_access[is_compute], pipeline);
          }
          if (zink_resource_access_is_write(res->barrier_access[is_compute]))