structuredClone invokes custom Map and Set iterators

Description

The React Native structuredClone polyfill traverses Map and Set values with for...of. An own Symbol.iterator override is therefore executed and can change the cloned contents or abort cloning, even though structured cloning should read the built-in collection data from internal slots.

Expected behavior

Map and Set cloning should ignore user iterator overrides and clone their real built-in entries, matching native structuredClone.

React Native Version

0.87.1 and current main

Affected Platforms

JavaScript runtime - All

从 React Native structuredClone polyfill 入手，检查 Map 和 Set 值的遍历方式。使用自定义的 Symbol.iterator 覆盖来复现问题，并将结果与原生 structuredClone 进行比较。完成标准是克隆使用内置条目，忽略这些覆盖，并在 JavaScript 运行时上保持预期行为。