If multiple compilation threads want to publish their generated code,
they currently block on each other. This can cause multiple background
threads to be blocked for several hundred milliseconds in the worst
case.

This CL changes this such that instead of blocking, the threads just
put the code in a queue from where it is picked up by the thread that
is currently publishing. Instead of blocking, the threads can then
continue compiling more code already.

This change might produce regressions, because there is now more
TurboFan tier-up compilation happening while Liftoff code is being
published. This might delay the completion of baseline compilation. It
can also happen that we publish (more) TurboFan code before finishing
baseline compilation, which would also regress compile scores.

Let's see what the perf bots have to say about this CL. We might need to
adapt certain things (like delaying TurboFan compilation until all
Liftoff code finished), or we might just accept slight delays in Liftoff
compilation, because tier-up will finish sooner after this CL, giving us
peak performance earlier.

R=ahaas@chromium.org

Bug: v8:10330
Change-Id: I2f5c15810a0a9fc18461f9cbf4e436ab36aa559d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2154200
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67308}