1) Instead of passing three boolean values to |TriggerCallbacks|, pass
   one EnumSet which contains all events to trigger.
2) Remember which events already happened, to avoid triggering them
   again.
3) Compute triggered events once after the loop in |OnFinishedUnits|,
   instead of checking for every finished unit.
4) When a new callback is registered, trigger all previous events
   immediately. This solves issue v8:10217.
5) Replace |NotifyTopTierReady| by |AddCallback| which is identical now.
6) Do not call |OnFinishedJSToWasmWrapperUnits| if no wrappers were
   compiled (this is a minor performance optimization; we save taking
   and releasing a lock).
7) Drive-by: Make the |EnumSet| constructor really constexpr (by making
   |Mask| constexpr).

R=ahaas@chromium.org

Bug: v8:10217
Change-Id: Ib3688a1687ad7b523e90efd73f4073e9f1193016
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2072737
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66459}