Until now, histograms associated with isolate counters were created
at the time of isolate initialization. This is too early because it
happens before persistent memory is configured. Histograms created
before persistent memory is set up are retrieved periodically but
infrequently and are not "flushed" on process termination. As a result,
a lot of samples from V8 are lost.

This CL implements lazy creation of counter histograms, the first time
that they are used.

Bug: chromium:1270428
Change-Id: I8540b50b6c3dde1f477853a011b6c3f2c2c6ef9d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3284888
Commit-Queue: Nikolaos Papaspyrou <nikolaos@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78125}