Data::Alias isn't that heavyweight I think... I know it's a bit largeish module, but unlike tie() its use imposes virtually no overhead at runtime, and very little at compile time (no source filter).

And it solves your problem nicely, and probably more efficiently than anything involving typeglobs:

alias my @bar = @$foo;

UPDATE: It actually benchmarks faster than local *bar = $foo on my machine, with the benefit of being truly lexically scoped.