This changes recording of compilation stats (i.e. code and reloc info
size) for each code object individually after it is finished, instead of
for the entire module. It avoids needed to iterate the code table which
would race with background tasks performing tier-up.

R=clemensh@chromium.org

Change-Id: Ic196fccb38b069a07e79fed4633d01dfc2639cd7
Reviewed-on: https://chromium-review.googlesource.com/1156396
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54816}