Add a regression test for issue-65934

Author: JohnTitor

src/test/ui/associated-types/issue-65934.rs

@@ -0,0 +1,17 @@
+// check-pass
+
+trait Trait {
+    type Assoc;
+}
+
+impl Trait for () {
+    type Assoc = ();
+}
+
+fn unit() -> impl Into<<() as Trait>::Assoc> {}
+
+pub fn ice() {
+    Into::into(unit());
+}
+
+fn main() {}