[llvm] [WIP][CodeGen] Encode liveness for COPY instructions after virtRegRewriter pass. (PR #151123)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:

>  This is in reference to [SWDEV-498533](https://ontrack-internal.amd.com/browse/SWDEV-498533)

Do not include any links in the upstream PRs that can't be accessible to all. This internal referencing is unwanted. Instead, explain the actual problem here.


https://github.com/llvm/llvm-project/pull/151123