Remove Servo window.trap() extension (#30743)

This Servo-specific extension is unused by any code in the repository
and removing it allows us to remove use of nightly only reliance on
rust intrinsics. This is a step toward supporting stable rust.

components/script/dom/webidls/Window.webidl

@@ -141,8 +141,6 @@ partial interface Window {
   [Pref="dom.servo_helpers.enabled"]
   undefined gc();
   [Pref="dom.servo_helpers.enabled"]
-  undefined trap();
-  [Pref="dom.servo_helpers.enabled"]
   undefined js_backtrace();
 };
 

components/script/dom/window.rs

@@ -1102,11 +1102,6 @@ impl WindowMethods for Window {
         }
     }
 
-    #[allow(unsafe_code)]
-    fn Trap(&self) {
-        unsafe { ::std::intrinsics::breakpoint() }
-    }
-
     #[allow(unsafe_code)]
     fn Js_backtrace(&self) {
         unsafe {

components/script/lib.rs

@@ -2,7 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-#![feature(core_intrinsics)]
 #![feature(drain_filter)]
 #![feature(once_cell)]
 #![feature(plugin)]