Revert of Invalidate the global property cell when converting from data to accessor. (patchset #1 id:1 of https://codereview.chromium.org/961003002/)

Reason for revert:
Breaks gc stress, e.g.: http://build.chromium.org/p/client.v8/builders/V8%20GC%20Stress%20-%201/builds/2322

Original issue's description:
> Invalidate the global property cell when converting from data to accessor.
>
> BUG=
> TBR=jkummerow@chromium.org,
>
> Committed: https://crrev.com/6a12dc240b1faffa500ff269077d832ecc74239d
> Cr-Commit-Position: refs/heads/master@{#26896}

TBR=jkummerow@chromium.org,verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/958113004

Cr-Commit-Position: refs/heads/master@{#26899}