This CL introduces a new pipeline mode in which each optimization
triggers both a Turbofan and an NCI compilation job. The TF code is
installed, the NCI code is inserted into the code cache for future
consumption by other contexts.

--turbo-nci enables this mode.

The old configuration (with NCI replacing TF) is still available under
the --turbo-nci-as-highest-tier flag. This flag remains useful for
testing purposes.

Drive-by: Refactor tracing in compiler.cc.

Bug: v8:8888
Change-Id: I62522e61788762250ff717eef84eae914e266f3b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2299360
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68983}