Store a flag per isolate whether new modules should be kept in
tiered-down state from the beginning. Adjust initial compilation if flag
is set.

Bug: v8:9654
Change-Id: I5aae435fb807f3eaa7efafe9af60451ad3c7e14d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2028452
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66321}