While we don't have full existential types yet, there is some duplication in privacy related errors for impl Trait

Author: oli-obk

src/test/compile-fail/private-type-in-interface.rs

@@ -35,6 +35,8 @@ type A = <m::Alias as m::Trait>::X; //~ ERROR type `m::Priv` is private
 trait Tr2<T> {}
 impl<T> Tr2<T> for u8 {}
 fn g() -> impl Tr2<m::Alias> { 0 } //~ ERROR type `m::Priv` is private
+//~^ ERROR type `m::Priv` is private
 fn g_ext() -> impl Tr2<ext::Alias> { 0 } //~ ERROR type `ext::Priv` is private
+//~^ ERROR type `ext::Priv` is private
 
 fn main() {}