jax

d927d96b - Raise a better error message if an empty mesh is passed to shard_map

Raise a better error message if an empty mesh is passed to shard_map Before: ``` ValueError: shard_map in_specs argument must refer to an axis marked as manual (frozenset()), but: in_specs refers to 'x' Check the in_specs values passed to shard_map. ``` After: ``` ValueError: shard_map requires a non-empty mesh. Got Mesh() ``` PiperOrigin-RevId: 857255016