Rename it to Symbolizer because it does exactly that.

Change the SymbolizeTickSample method to return the symbolized state
rather than pass it on to the ProfilesCollection. This makes it easier
to test as now it only relies on the CodeMap provided to it.

Make EntryForVMState a free-floating function as it doesn't rely on
state and then we can avoid importing the StateTag definition in the
header.

Remove the UNREACHABLE from EntryForVMState as the compiler got smarter
and doesn't need it anymore.

Pass the CpuProfilesCollection to SamplingEventsProcessor instead,
as it is now responsible for putting the symbolized samples into the
collection to be sorted into the appropriate profiles.

Change-Id: I104290eff22b7d94a1bd34ba904036badccf4e13
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440522
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70248}