Add more test case to existing one

Author: yuk1ty

tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs

@@ -1,5 +1,6 @@
-// We should not emit sealed traits note, see issue #143392
+// We should not emit sealed traits note, see issue #143392 and #143121
 
+/// Reported in #143392
 mod inner {
     pub trait TraitA {}
 
@@ -10,4 +11,13 @@ struct Struct;
 
 impl inner::TraitB for Struct {} //~ ERROR the trait bound `Struct: TraitA` is not satisfied [E0277]
 
+/// Reported in #143121
+mod x {
+    pub trait A {}
+    pub trait B: A {}
+
+    pub struct C;
+    impl B for C {} //~ ERROR the trait bound `C: A` is not satisfied [E0277]
+}
+
 fn main(){}

tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr

@@ -15,6 +15,23 @@ note: required by a bound in `TraitB`
 LL |     pub trait TraitB: TraitA {}
    |                       ^^^^^^ required by this bound in `TraitB`
 
-error: aborting due to 1 previous error
+error[E0277]: the trait bound `C: A` is not satisfied
+  --> $DIR/false-sealed-traits-note.rs:18:16
+   |
+LL |     impl B for C {}
+   |                ^ the trait `A` is not implemented for `C`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/false-sealed-traits-note.rs:14:5
+   |
+LL |     pub trait A {}
+   |     ^^^^^^^^^^^
+note: required by a bound in `B`
+  --> $DIR/false-sealed-traits-note.rs:15:18
+   |
+LL |     pub trait B: A {}
+   |                  ^ required by this bound in `B`
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.