LibJS: Implement Atomics.isLockFree

Author: https://github.com/trflynn89
Commit: 1a3e1bff7b
Pull-request: https://github.com/SerenityOS/serenity/pull/8752
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibJS/Runtime/AtomicsObject.h

@@ -23,6 +23,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(and_);
     JS_DECLARE_NATIVE_FUNCTION(compare_exchange);
     JS_DECLARE_NATIVE_FUNCTION(exchange);
+    JS_DECLARE_NATIVE_FUNCTION(is_lock_free);
     JS_DECLARE_NATIVE_FUNCTION(load);
     JS_DECLARE_NATIVE_FUNCTION(or_);
     JS_DECLARE_NATIVE_FUNCTION(store);