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

[Christudasan Devadasan via llvm-commits]

https://github.com/cdevadas commented:

This patch changes the definition of the COPY instruction. It needs the attention of a wider audience. You should include some folks from the community who review the CodGen changes. 

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