This is a reland of 72b88fda
Original change's description:
> [runtime] Make all built-in functions strict.
> 
> According to ES#sec-built-in-function-objects all built-in functions
> must be strict.
> 
> This is a preliminary CL before changing the way we define built-in
> functions in native JS files.
> 
> Bug: v8:6529, v8:6459
> Change-Id: I8e60b342f04ea1b0843fe1990334cbb9b26ebac4
> Reviewed-on: https://chromium-review.googlesource.com/546215
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Adam Klein <adamk@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46237}

Bug: v8:6529, v8:6459
Change-Id: Ic0eb3d7925ed63dd716c4a114601415f92627ca5
Reviewed-on: https://chromium-review.googlesource.com/550156Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46262}