Added public API sealed in trait_unsafe_added lint (#1158)

Resolves #1116

Author: geetanshjuneja

src/lints/trait_unsafe_added.ron

@@ -13,7 +13,7 @@ SemverQuery(
                     ... on Trait {
                         visibility_limit @filter(op: "=", value: ["$public"]) @output
                         unsafe @filter(op: "!=", value: ["$true"])
-                        unconditionally_sealed @filter(op: "!=", value: ["$true"])
+                        public_api_sealed @filter(op: "!=", value: ["$true"])
 
                         importable_path {
                             path @output @tag

test_crates/trait_unsafe_added/new/src/lib.rs

@@ -25,3 +25,8 @@ mod private {
 
 // Sealed trait, becoming unsafe doesn't matter since it cannot be implemented downstream.
 pub unsafe trait SealedTrait: private::Sealed {}
+
+pub unsafe trait PublicAPISealed {
+    #[doc(hidden)]
+    type Hidden;
+}

test_crates/trait_unsafe_added/old/src/lib.rs

@@ -25,3 +25,8 @@ mod private {
 
 // Sealed trait, becoming unsafe doesn't matter since it cannot be implemented downstream.
 pub trait SealedTrait: private::Sealed {}
+
+pub trait PublicAPISealed {
+    #[doc(hidden)]
+    type Hidden;
+}