Dynamic index generation used as starting seend boosts performance for
Jobs that have many work items. This is taken from
https://source.chromium.org/chromium/chromium/src/+/master:base/task/job_perftest.cc;l=30?q=job_perftest&ss=chromium

Change-Id: Ie1ba432808f07498f90ab4c0af419b8f9b72e342
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2405799
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69854}