[llvm] [CodeGen][MISched] Handle empty sized resource usage. (PR #75951)

[Francesco Petrogalli via llvm-commits]

https://github.com/fpetrogalli approved this pull request.

One more comment, either remove the "empty interval optimisation", or expand the comment to make clear it is an optimization and not a functional change.

Approved, thank you for your patience!

https://github.com/llvm/llvm-project/pull/75951