There's no need to set it so early - it's only needed when the function has
really been parsed. This way we don't need to produce and store it for skipped
inner functions.

BUG=v8:5516

Change-Id: Ibf59a8acb886ea3de9be140431a334a03b408f5b
Reviewed-on: https://chromium-review.googlesource.com/461827
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44410}