Instead, just return undefined.

A side effect of this is that it's no longer possible to compile
functions in a detached context.

Based on https://codereview.chromium.org/294073002 but taking access
check callbacks into account

BUG=chromium:541703
R=verwaest@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/1393713006

Cr-Commit-Position: refs/heads/master@{#31208}