It enables jobs without a SharedFunctionInfo.

BUG=v8:6093

Change-Id: Icc5f01512c270a55349087d418b6be82ad5c6cb4
Reviewed-on: https://chromium-review.googlesource.com/467148
Commit-Queue: Wiktor Garbacz <wiktorg@google.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44402}