This patch adds the newly added support for contexts in V8 Tracing, as well
as use it to mark all the entry points for a V8 Isolate.

Update for reland: The current tracing interface needs to be updated (AddTraceEvent),
but the embedders need to migrate to the new version before removing the old version.
(Reland of: https://codereview.chromium.org/1686233002)

The revert happened because the 2 signatures of the old and new AddTraceEvent where different
so it threw an overload-virtual error on cross arm debug. This issue is temporary, and to solve
it, I added an implementation of the old and new everywhere until the embedder implements the new.

BUG=v8:4565
LOG=N

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1704253002

Cr-Commit-Position: refs/heads/master@{#34332}