Add tests for issue knurling-rs#799

defmt/tests/derive-bounds.rs

@@ -0,0 +1,29 @@
+fn main() {
+    let baz: Baz<Qux> = Default::default();
+    defmt::info!("{}", baz);
+}
+
+trait Foo {
+    type Bar;
+}
+#[derive(defmt::Format, Default)]
+struct Baz<T: Foo> {
+    field: T::Bar,
+    field2: Quux<T>,
+}
+#[derive(defmt::Format, Default)]
+struct Qux;
+impl Foo for Qux {
+    type Bar = Qux;
+}
+#[allow(dead_code)]
+#[derive(defmt::Format, Default)]
+enum Quux<T: Foo> {
+    #[default]
+    None,
+    Variant1(T),
+    Variant2 {
+        f: T::Bar,
+    },
+    Variant3(T::Bar),
+}

defmt/tests/ui.rs

@@ -9,5 +9,6 @@ fn ui() {
         t.compile_fail("tests/ui/*.rs");
 
         t.pass("tests/basic_usage.rs");
+        t.pass("tests/derive-bounds.rs");
     }
 }