This is a reland of 6da438fd

Original change's description:
> [runtime] introduced instrance type for each context type
> 
> Each context type get own instance type:
> - we can make CSA checks more strict in couple places,
> - it is requires step for advanced evaluation without side effects.
> 
> R=yangguo@chromium.org
> 
> Bug: v8:7588
> Change-Id: I585e8b55a280a909fc3c6069ed30e34b7040d0c7
> Reviewed-on: https://chromium-review.googlesource.com/977041
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#52191}

Bug: v8:7588
Change-Id: I80110ff814c0315d7ca694b7d0aef5b10df614f0
Reviewed-on: https://chromium-review.googlesource.com/978584Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52196}