Add a test for a GAT ICE with self-referential lifetime bounds

Author: jakubadamw

tests/ui/generic-associated-types/ice-add-outlives-bounds-unexpected-regions-113793.rs

@@ -0,0 +1,26 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/113793>.
+//!
+//! Using a GAT with a self-referential lifetime bound (`'b: 'b`) in a
+//! fully-qualified path with anonymous lifetimes used to ICE.
+
+//@ check-pass
+
+trait Gat {
+    type FooArg<'a, 'b: 'b>;
+}
+
+impl Gat for () {
+    type FooArg<'a, 'b: 'b> = &'a dyn ToString;
+}
+
+struct Test;
+
+impl Iterator for Test {
+    type Item = Box<dyn Fn(<() as Gat>::FooArg<'_, '_>)>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        None
+    }
+}
+
+fn main() {}