LibJS: Add spec comments to TypedArray.prototype.keys

Author: https://github.com/jamierocks
Commit: https://github.com/SerenityOS/serenity/commit/67ed3e1d93
Pull-request: https://github.com/SerenityOS/serenity/pull/16117
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp

@@ -783,7 +783,11 @@ JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::keys)
 {
     auto& realm = *vm.current_realm();
 
+    // 1. Let O be the this value.
+    // 2. Perform ? ValidateTypedArray(O).
     auto* typed_array = TRY(validate_typed_array_from_this(vm));
+
+    // 3. Return CreateArrayIterator(O, key).
     return ArrayIterator::create(realm, typed_array, Object::PropertyKind::Key);
 }