add test case

Author: nikomatsakis

src/test/ui/async-await/issue-84841.rs

@@ -0,0 +1,10 @@
+// edition:2018
+
+async fn main() {
+    // Adding an .await here avoids the ICE
+    test()?;
+}
+
+// Removing the const generic parameter here avoids the ICE
+async fn test<const N: usize>() {
+}