`using` transform throws when a for body binding shadows the for head binding

🔎 Search Terms

explicit resource management, using, await using, loop initializer, Symbol.dispose, Symbol.asyncDispose, iteration, shadows

🕗 Version & Regression Information

• This changed between versions ______ and _______
• This changed in commit or PR _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about https://github.com/microsoft/TypeScript/wiki/FAQ#common-bugs-that-arent-bugs
• I was unable to test this on prior versions because _______

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.9.0-dev.20250516#code/MYGwhgzhAEBiD29oG8C+BYAUAM3gJ2gAoBXCASwDsBzaXJebaAbQF0BKFLaaYeCiAC61E0ALzQKAUwDucRITYBuLKiA

💻 Code

class Foo {}
for (using foo of []) {
  const foo = new Foo();
}

🙁 Actual behavior

The transformed output throws "redeclaration of const foo "

🙂 Expected behavior

The transformed output should not throw.

Additional information about the issue

Babel is also affected by this issue: https://github.com/babel/babel/issues/17318. We plan to wrap the for body within a new block when it contains shadowed binding.