The function index encoded into the serialized module is already offset
by num_imported_functions. For lazy compilation, however, we added the
number of imported functions another time, which was incorrect.

R=clemensb@chromium.org

Change-Id: I56380e21e74b4d1935ebdbab6ef8cc388de49f2c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3172761
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76965}