See related CL for context.

Changes:
- In InitExprInterface, add the ability to evaluate function references
  as index only. Remove the global buffers and use the ones passed with
  the instance object instead.
- In WasmElemSegment, add a field indicating if elements should be
  parsed as expressions or indices. Change module-decoder.cc to reflect
  this change.
- In module-instantiate, change the signatures of LoadElemSegment,
  LoadElemSegmentImpl, and EvaluateInitExpr. Move the latter out of
  InstanceBuilder.

Change-Id: I1df54393b2005fba49380654bdd40429bd4869dd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3364081Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78470}