This skips one level of indirection by calling the off-heap entry
point directly instead of going through the on-heap Code trampoline.

Bug: v8:7777
Change-Id: If667ea6cd6138ab1c12aa861ef441109008e4fba
Reviewed-on: https://chromium-review.googlesource.com/c/1382459Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58324}