The compilation state should have no notion of Isolates. Move code
logging and management of the corresponding foreground task to the
WasmEngine.

R=mstarzinger@chromium.org

Bug: v8:8689
Change-Id: Ib690317139d0754731b9f0e71d06e7a722082eed
Reviewed-on: https://chromium-review.googlesource.com/c/1434035
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59093}