JS Iterators, generators, and destructuring · Pull Request #275 · pierrelf.com/we

Implements issue 3mhn3peabad2h ## Summary - **Generator functions**: `function*`, `yield`, `yield*`, `generator.next(value)`, `generator.return(value)`, `generator.throw(error)` - **Iterator protocol**: `Symbol.iterator` (`@@iterator`), `for...of` loops using the iterator protocol - **Built-in iterators**: `Array.prototype[@@iterator]`, `String.prototype[@@iterator]`, `Map.prototype[@@iterator]`, `Set.prototype[@@iterator]`, plus `keys()`/`values()`/`entries()` returning proper iterators - **Destructuring fixes**: Fixed register allocation LIFO violations, added rest elements for both array (`[a, ...rest]`) and object (`{a, ...rest}`) destructuring - **Spread operator**: `[...arr]` in array literals using the iterator protocol - **Bytecode**: Added `Yield` and `Spread` opcodes, `is_generator` flag on Function - **25 new tests** covering generators, for...of, destructuring, spread, and custom iterables All 495 JS unit tests pass. Clippy clean. Formatted.