Those have been effectively unused for quite a while now, and we
don't see any use in having them around. Actually it'd be way more
consistent and simpler to just use OtherInternal as type for contexts
instead.

R=mvstanton@chromium.org
BUG=v8:5267,v8:5270

Review-Url: https://codereview.chromium.org/2305383002
Cr-Commit-Position: refs/heads/master@{#39166}