This adds a flag to {WasmCode} objects to store whether this code was
generated for debugging. This flag can be set for Liftoff code (in which
case the code will e.g. have an extended prologue for debugging), but it
can also be set for TurboFan, in case Liftoff bailed out when producing
the debugging code.

Having this flag allows us to remove the hack to pass the compilation
results to {OnFinishedUnits} just to check whether we actually wanted to
compile Liftoff functions.

Drive-by: Replace the {ReachedRecompilationTierField} by a
{MissingRecompilationField}, because all we need to know is if we are
still waiting for that function to get recompiled.

R=ahaas@chromium.org

Bug: v8:10330,v8:10410
Change-Id: Ia023df8955a60d9f5595a6cb2737e14d83baf716
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2142259
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67119}