lduAddressing::losortStart incorrect for cells without upper

Summary

lduAddressing losortStart does not assign to cells that do not have higher numbered neighbours.

Steps to reproduce

Take case, renumberMesh with random. Check losortStart for any zeros.

Example case

Not yet found one.

What is the current bug behaviour?

losortStart set to 0.

Environment information

• OpenFOAM version : v2412

Possible fixes

Initialise to faces size.