This flag allows you to filter printing Wasm code to one particular
function index.

Bug: v8:10791
Change-Id: I400ccaadb8330e5e31e2faefdeddb169cdc85f71
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2459259
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70457}