Revert "Update Binaryen to 4ec79ce9826d96225d33dec77dfc344adab92606"

This reverts commit c30bec0f1a31bd1fccfcd535153d8b8075f6ed1a.

Reason for revert: Broke RISC V build

Original change's description:
> Update Binaryen to 4ec79ce9826d96225d33dec77dfc344adab92606
>
> The encoding for stringref instructions has been updated to match V8.
>
> This is the version right before the change to output the new
> encoding for `br_on_cast[_fail]` instructions with input immediate.
>
> Change-Id: I0ac1cb81e3529b7d903dbf7c6232383d6af46ed0
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/309860
> Commit-Queue: Aske Simon Christensen <askesc@google.com>
> Reviewed-by: Ömer Ağacan <omersa@google.com>

Change-Id: Iea0f3ef76f98fbc9a2baed525060883e1aacb274
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/310300
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Auto-Submit: Aske Simon Christensen <askesc@google.com>
Reviewed-by: Ömer Ağacan <omersa@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>