Recent changes in wasm-module-builder.js were not translated to the
fuzzer JS output. After this CL, the fuzzer should generate .js files
that output back the fuzzed module.

Change-Id: I8bc33ab7f4f838a519c7aa47e425d8ac65b88d45
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2904217
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74659}