[llvm] [CodeGen] Add laneBitmask as new MachineOperand type, utilised by newly defined COPY_LANEMASK instruction (PR #151944)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:


> So, should I still go with RFC explaining above point & the one given by Matt, along with its potential use-cases inf future.

That would be good.

https://github.com/llvm/llvm-project/pull/151944