Auto merge of #80569 - notriddle:patch-3, r=jyn514

Use Array.prototype.filter instead of open-coding

Part of #79052, originally suggested in https://github.com/rust-lang/rust/pull/79052#discussion_r523468743 by `@jyn514`

Besides making main.js smaller (always a plus), this also performs better by using the optimized filter implementation in your browser's JavaScript engine (according to `@GuillaumeGomez,` an 84% performance improvement).