Don't re-log all existing functions during StartProcessorIfNotStarted().
They will already be in the CodeMap attached to the ProfileGenerator and
re-logging them causes leaks. See the linked bug for more details.

Bug: v8:8253
Change-Id: Ibb1a1ab2431c588e8c3a3a9ff714767cdf61a88e
Reviewed-on: https://chromium-review.googlesource.com/1256763
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56336}