We currently have the problem that we trigger too many code GCs since
{new_potentially_dead_code_size_} is never reset to zero.
This CL adds a counter which tells us how many GCs we ran per native
module. This counter is sampled on each code GC. It will give us a
good understanding of the amount of GC work we are executing in the
wild. The number should stay in the single-digits generally.

R=mstarzinger@chromium.org, mpearson@chromium.org

Bug: v8:8217
Change-Id: I978a98dff76e0f466ff51e067626886b58d52ded
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1615246Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61611}