Provide a `--logdir` option to `Tools/wasm/wasi`

[brettcannon]

Right now, Tools/wasm/wasi writes any log files when --quiet is specified to tempfile.gettempdir(), but there's no reason to hard-code it. So adding a --logdir option to specify the directory seems to make sense.

Linked PRs

• GH-137248: Add a --logdir option to Tools/wasm/wasi #137249
• [3.14] GH-137248: Add a --logdir option to Tools/wasm/wasi (GH-137249) #137252

[brettcannon]

FYI this is essentially done; just leaving it open until I can merge the backport into 3.14.