This is a reland of b90e83f5
Original change's description:
> [runtime] Add shortcuts for elements kinds transitions.
>
> The shortcuts ensure that field type generalization is properly
> propagated in the transition graph.
>
> Bug: chromium:738763
> Change-Id: Id701a6f95ed6ea093c707fbe0bac228f1f856e9f
> Reviewed-on: https://chromium-review.googlesource.com/567992
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46622}

Bug: chromium:738763, chromium:742346, chromium:742381, chromium:745844
Change-Id: I93974e3906b2c7710bd525f15037a2dd97f263ad
Reviewed-on: https://chromium-review.googlesource.com/575227
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46759}