This mostly reverts commit c503b805 but fixes
an issue where literals would always be pretenured on first instantiation.

As a cleanup we pass in a PretenureFlag instead of using the FeedbackVector as
indicator.

Bug: v8:6211
Change-Id: Id328552620e33f5083519bcba1e24396d162d516
Reviewed-on: https://chromium-review.googlesource.com/555670Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46342}