New trace events:

- finished OSR compilation.
- entry into OSR code.

Since the latter now happens without a trip into runtime, tracing is a
bit more involved - we need to check FLAG_trace_osr in generated code,
and call a runtime function if it is set.

Drive-by: Slightly reorganize other OSR tracing.

Bug: v8:12161
Change-Id: I3096424ca7d47a19802281a0e0a39f7f3394c12b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3629331
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Auto-Submit: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80420}