Basically it uses bind mounts instead. See this page for details.

I haven’t actually used (since Plan 9 is dead) and I doubt it covers every use case for symlinks (e.g. this wouldn’t let you commit them to a git repo), but I really think the benefits of symlinks not existing at all would far outweigh the effort of having to think of alternative solutions.

Sadly we don’t get to live in that alternative history now… :-/