Merge #340

340: print usage required during usage validation r=kvark a=m4b

fixes #339

Co-authored-by: m4b <m4b.github.io@gmail.com>

wgpu-native/src/device.rs

@@ -1215,7 +1215,7 @@ pub fn device_create_bind_group<B: GfxBackend>(
                         .buffers
                         .use_extend(&*buffer_guard, bb.buffer, (), usage)
                         .unwrap();
-                    assert!(buffer.usage.contains(usage));
+                    assert!(buffer.usage.contains(usage), "Expected buffer usage {:?}", usage);
 
                     let end = if bb.size == 0 {
                         None