LibJS: Implement Function.prototype.bind()

Author: https://github.com/jack-karamanian
Commit: 1fa0c7304d
Pull-request: https://github.com/SerenityOS/serenity/pull/1863
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/linusg

Libraries/LibJS/AST.cpp

@@ -114,9 +114,8 @@ Value CallExpression::execute(Interpreter& interpreter) const
     auto& function = static_cast<Function&>(callee.as_object());
 
     MarkedValueList arguments(interpreter.heap());
-    for (auto bound_argument : function.bound_arguments()) {
-        arguments.append(bound_argument);
-    }
+    arguments.values().append(function.bound_arguments());
+
     for (size_t i = 0; i < m_arguments.size(); ++i) {
         auto value = m_arguments[i].execute(interpreter);
         if (interpreter.exception())