Add ignored test for associated types in const impl

src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs

@@ -0,0 +1,28 @@
+// ignore-test
+
+// FIXME: This test should fail since, within a const impl of `Foo`, the bound on `Foo::Bar` should
+// require a const impl of `Add` for the associated type.
+
+#![allow(incomplete_features)]
+#![feature(const_trait_impl)]
+#![feature(const_fn)]
+
+struct NonConstAdd(i32);
+
+impl std::ops::Add for NonConstAdd {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Self {
+        NonConstAdd(self.0 + rhs.0)
+    }
+}
+
+trait Foo {
+    type Bar: std::ops::Add;
+}
+
+impl const Foo for NonConstAdd {
+    type Bar = NonConstAdd;
+}
+
+fn main() {}