Remove unused function {UseLazyStubs}. Lazy compile stubs are now set on
a per function basis. This made the function {UseLazyStubs} redundant.

Change-Id: I8e715d6a9774c39841219c04c42364fc2e964569
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1588473
Commit-Queue: Frederik Gossen <frgossen@google.com>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61124}