This commit allows inlining of Array#indexOf and Array#includes when the array type is polymorphic for types that are compatable for array iteration.

Bug: v8:8388
Change-Id: Ib826bad857c7dfe0ee7af99bb456b50b7a8b6ef9
Reviewed-on: https://chromium-review.googlesource.com/c/1450137
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59473}