Revert of [test262-es6] Temporary disable some tests (patchset #1 id:1 of https://codereview.chromium.org/1176573002/)

Reason for revert:
[Sheriff] Prepares revert of https://codereview.chromium.org/1136553008

Original issue's description:
> [test262-es6] Temporary disable some tests
>
> These tests have issues with our harness.
>
> Upstream fix: https://github.com/tc39/test262/pull/309
>
> BUG=N
> LOG=N
> TBR=machenbach@chromium.org
>
> Committed: https://crrev.com/eed7363a0da0f21c3eee6c052507299d9b707462
> Cr-Commit-Position: refs/heads/master@{#28881}

TBR=arv@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=N

Review URL: https://codereview.chromium.org/1169903006

Cr-Commit-Position: refs/heads/master@{#28889}