LibJS: Convert %IteratorPrototype% to ThrowCompletionOr

Userland/Libraries/LibJS/Runtime/IteratorPrototype.cpp

@@ -20,7 +20,7 @@ void IteratorPrototype::initialize(GlobalObject& global_object)
     auto& vm = this->vm();
     Object::initialize(global_object);
     u8 attr = Attribute::Writable | Attribute::Enumerable;
-    define_old_native_function(*vm.well_known_symbol_iterator(), symbol_iterator, 0, attr);
+    define_native_function(*vm.well_known_symbol_iterator(), symbol_iterator, 0, attr);
 }
 
 IteratorPrototype::~IteratorPrototype()
@@ -28,10 +28,9 @@ IteratorPrototype::~IteratorPrototype()
 }
 
 // 27.1.2.1 %IteratorPrototype% [ @@iterator ] ( ), https://tc39.es/ecma262/#sec-%iteratorprototype%-@@iterator
-JS_DEFINE_OLD_NATIVE_FUNCTION(IteratorPrototype::symbol_iterator)
+JS_DEFINE_NATIVE_FUNCTION(IteratorPrototype::symbol_iterator)
 {
-    auto* this_object = TRY_OR_DISCARD(vm.this_value(global_object).to_object(global_object));
-    return this_object;
+    return TRY(vm.this_value(global_object).to_object(global_object));
 }
 
 }

Userland/Libraries/LibJS/Runtime/IteratorPrototype.h

@@ -19,7 +19,7 @@ public:
     virtual ~IteratorPrototype() override;
 
 private:
-    JS_DECLARE_OLD_NATIVE_FUNCTION(symbol_iterator);
+    JS_DECLARE_NATIVE_FUNCTION(symbol_iterator);
 };
 
 }