Added test for issue.

src/test/ui/associated-type-bounds/issue-61752.rs

@@ -0,0 +1,24 @@
+// run-pass
+
+#![feature(associated_type_bounds)]
+
+trait Foo {
+    type Bar;
+}
+
+impl Foo for () {
+    type Bar = ();
+}
+
+fn a<F: Foo>() where F::Bar: Copy {}
+
+fn b<F: Foo>() where <F as Foo>::Bar: Copy {}
+
+// This used to complain about ambiguous associated types.
+fn c<F: Foo<Bar: Foo>>() where F::Bar: Copy {}
+
+fn main() {
+    a::<()>();
+    b::<()>();
+    c::<()>();
+}