- Get rid of a bunch of unnecessary friend classes. This required making
  the constructor public
- Remove log_events_ field which is not used
- Use unique_ptr for owned members
- Use make_unique instead of bare constructors
- Use a scoped vector instead of a unique ptr to array for
  the dynamically sized array of WasmModules

Bug: v8:9396
Change-Id: Icdca904e7227d2ce2d75caf092f259d47ff15809
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1803339Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63776}