amend to Switch can_eq and can_sub to DefineOpaqueTypes::Yes

Author: oli-obk

tests/ui/impl-trait/nested_impl_trait.rs

@@ -5,7 +5,7 @@ fn fine(x: impl Into<u32>) -> impl Into<u32> { x }
 
 fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x }
 //~^ ERROR nested `impl Trait` is not allowed
-//~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
+//~| ERROR the trait bound `impl Into<u32>: Into<impl Debug>` is not satisfied
 
 fn bad_in_fn_syntax(x: fn() -> impl Into<impl Debug>) {}
 //~^ ERROR nested `impl Trait` is not allowed
@@ -18,7 +18,7 @@ struct X;
 impl X {
     fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x }
     //~^ ERROR nested `impl Trait` is not allowed
-    //~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
+    //~| ERROR the trait bound `impl Into<u32>: Into<impl Debug>` is not satisfied
 }
 
 fn allowed_in_assoc_type() -> impl Iterator<Item=impl Fn()> {