Prior to 69debbb5, InstallGetterSetter
was bugged and ignored all passed attributes, installing as DONT_ENUM
instead. This commit makes sure we match old behavior now that that bug
is fixed.

BUG=v8:5339

Review-Url: https://codereview.chromium.org/2316513003
Cr-Commit-Position: refs/heads/master@{#39191}