Allow to self reference associated types in where clauses

src/test/ui/associated-type-bounds/super-trait-referencing-self.rs

@@ -0,0 +1,12 @@
+// check-pass
+trait Foo {
+    type Bar;
+}
+trait Qux: Foo + AsRef<Self::Bar> {}
+trait Foo2 {}
+
+trait Qux2: Foo2 + AsRef<Self::Bar> {
+    type Bar;
+}
+
+fn main() {}