add test for lifetime inside generator witness

Author: csmoe

src/test/ui/async-await/issues/issue-64552.rs

@@ -0,0 +1,18 @@
+// edition: 2018
+
+async fn use_async<T>(_val: T) {}
+
+struct MyStruct<'a, T: 'a> {
+    val: &'a T
+}
+
+unsafe impl<'a, T: 'a> Send for MyStruct<'a, T> {}
+
+async fn use_my_struct(val: MyStruct<'static, &'static u8>) {
+    use_async(val).await;
+}
+
+fn main() {
+    let first_struct: MyStruct<'static, &'static u8> = MyStruct { val: &&26 };
+    needs_send(use_my_struct(second_struct));
+}