update compile-fail tests: fewer warnings because this is now a HIR lint

Author: RalfJung

src/test/compile-fail/issue-17994.rs

@@ -10,5 +10,4 @@
 
 trait Tr {}
 type Huh<T> where T: Tr = isize; //~  ERROR type parameter `T` is unused
-                                 //~| WARNING where clauses are not enforced in type aliases
 fn main() {}

src/test/compile-fail/private-in-public-warn.rs

@@ -58,7 +58,6 @@ mod traits {
     pub trait PubTr {}
 
     pub type Alias<T: PrivTr> = T; //~ ERROR private trait `traits::PrivTr` in public interface
-    //~^ WARNING bounds on generic parameters are not enforced in type aliases
     //~| WARNING hard error
     pub trait Tr1: PrivTr {} //~ ERROR private trait `traits::PrivTr` in public interface
     //~^ WARNING hard error
@@ -85,7 +84,6 @@ mod traits_where {
     pub type Alias<T> where T: PrivTr = T;
         //~^ ERROR private trait `traits_where::PrivTr` in public interface
         //~| WARNING hard error
-        //~| WARNING where clauses are not enforced in type aliases
     pub trait Tr2<T> where T: PrivTr {}
         //~^ ERROR private trait `traits_where::PrivTr` in public interface
         //~| WARNING hard error