Test case for rust-lang#62506.

Author: gilescope

src/test/ui/generator/issue-62506-two_awaits.rs

@@ -0,0 +1,18 @@
+// Output = String caused an ICE whereas Output = &'static str compiled successfully.
+// Broken MIR: generator contains type std::string::String in MIR,
+// but typeck only knows about {<S as T>::Future, ()}
+// check-pass
+// edition:2018
+
+#![feature(async_await)]
+use std::future::Future;
+
+pub trait T {
+    type Future: Future<Output = String>;
+    fn bar() -> Self::Future;
+}
+pub async fn foo<S>() where S: T {
+    S::bar().await;
+    S::bar().await;
+}
+pub fn main() {}