Suppress lld 16 errors about undefined symbols in version maps
lld >= 16 turned on --no-undefined-version by default, which results in
errors whenever symbols are mentioned in version maps, but are not
actually defined in the binary.
Since we have quite a few instances of symbols that are defined or not,
depending on various compile-time settings, suppress this lld check for
the time being.
MFC after: 1 week
(cherry picked from commit 2ba84b4bcdd6012e8cfbf8a0d060a4438623a638)