Revert of Disable non-standard Promise functions in staging (patchset #5 id:80001 of https://codereview.chromium.org/1469543003/ )

Reason for revert:
[Sheriff] This breaks ignition on arm sim debug:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/builds/5317

Seems to not be caught by the cq bot that builds release with dchecks.

Original issue's description:
> Disable non-standard Promise functions in staging
>
> This patch removes Promise functions and methods which are absent
> from the ES2015 specification when the --es-staging flag is on.
>
> BUG=v8:3237
> R=rossberg
> LOG=Y
>
> Committed: https://crrev.com/941251af7e04d50ac2243da2870249a42111221a
> Cr-Commit-Position: refs/heads/master@{#32194}

TBR=rossberg@chromium.org,littledan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3237

Review URL: https://codereview.chromium.org/1473603002

Cr-Commit-Position: refs/heads/master@{#32199}