Auto-drop borrows

In https://github.com/bytecodealliance/jco/pull/262, we now validate all borrows properly.

The need to call `resource[Symbol.dispose]()` explicitly for all functions that take resources seems unnecessary though.

Rather, the implementation should always auto-drop borrows at the bindgen level without requiring the JS user to have to do that explicitly. Explicitly drop calls should instead act as early drops if desired.

首先阅读 PR 262 以及它修改的 bindgen 实现，因为该 issue 没有指出任何文件或测试。跟踪借用资源如何被验证和丢弃，然后将完成定义为对获取资源的函数自动丢弃借用，同时显式的 Symbol.dispose() 调用仍可作为提前丢弃的方式使用。

由索引模型根据 Issue 内容生成。