In order to get a more complete picture about the code sizes of
compiled wasm modules, sample the code size of each module after
top-tier compilation finished. This happens via the {WasmEngine}
because that's where we know which isolates use a given {NativeModule}
and can schedule foreground tasks to sample the code size.

R=mstarzinger@chromium.org

Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel
Bug: v8:8217
Change-Id: Id585db8a9ab8f3aa1060b08411afaa31c5414f87
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1508404
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60167}