We introduce the WasmInliningHeuristics virtual class and implement it
with a trivial heuristics that inlines direct calls based on callee
index only. Other, more meaningful heuristics will be introduced later.

Bug: v8:12166
Change-Id: I74fd8f61e0c97b975827fa062629e9ff7463e058
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3157952
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76816}