[turbofan] Reland^2 "Polymorphic inlining - try merge map check dispatch with function call dispatch."

This reverts commit e26e6d88.

Bug: chromium:758096
Change-Id: I1d8ecda995c93c84a9a3c24da041fdb730dbd3b2
Reviewed-on: https://chromium-review.googlesource.com/628169Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47812}