Moved tests for IIFEs/top level code to AllocationSiteCreationForIIFE.
It is not possible to use %EnsureFeedbackVector for these tests. They
just turn the lazy_feedback_allocation flag to false.

Bug: v8:8394
Change-Id: Id18cb43bf350efc1a26d04b9c3fce4f638dbda84
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1601507
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61376}