This brings the WasmModuleBuilder in the mjsunit test suite
up to date wrt. the latest changes of the GC proposal.

Bug: v8:7748
Change-Id: I4e1a3d34a1e83626ab89d2fa0e10ca4aa61d75ea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2690590
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73496}