fix: stdout and stderr encoding on Windows

[dsherret]

Given:

const encoder = new TextEncoder();

// stdout
{
  console.log("你好，世界");
  const size = await Deno.stdout.write(encoder.encode("🦕\n"));
  if (size !== 5) {
    throw new Error();
  }
}

// stderr
{
  console.error("你好，世界");
  const size = await Deno.stderr.write(encoder.encode("🦕\n"));
  if (size !== 5) {
    throw new Error();
  }
}

Before:

õ¢áÕÑ¢´╝îõ©ûþòî
­ƒªò
õ¢áÕÑ¢´╝îõ©ûþòî
­ƒªò

After:

你好，世界
🦕
你好，世界
🦕

Closes #6001
Closes #14516
Closes #14545

[dsherret]

I tried to add a test for this, but whatever I tried passed before and after (I think probably because our test utilitity collects data with a pipe and so it's not a console and doesn't get this special behaviour applied)

Edit: Nevermind. Added a pty test.

[ry]

LGTM - lack of test is unfortunate but I don't have any suggestions...

[ry]

regarding the TODO is it possible to close stdout after this patch?

[dsherret]

No, not possible still. I removed the todo because I didn't think it was worth keeping it in the code since I think doing this will arise from the need to do it.

[dsherret]

Actually, Bartek had the good idea of testing this in a pty and I just thought to repurpose the repl tests for this. I just tried it out and it fails on main, but passes on this branch. The downside of course is that it doesn't run on the CI, but better than nothing.

[bartlomieju]

LGTM

[bartlomieju]

Nice 👍