handle ByRef in relate

src/test/ui/const-generics/issues/issue-68615-array.rs

@@ -0,0 +1,11 @@
+// check-pass
+#![feature(const_generics)]
+#![allow(incomplete_features)]
+
+struct Foo<const V: [usize; 0] > {}
+
+type MyFoo = Foo<{ [] }>;
+
+fn main() {
+    let _ = Foo::<{ [] }> {};
+}