[clang] [llvm] [ABI] Add IndirectAliased kind to abi::ArgInfo (PR #225005)

[via llvm-commits]

skc7 wrote:

> What is the use-case for this distinction? Do you have a follow-up patch that shows it in-use?

The consumer is the AMDGPU classifier in #220177. 
Large and kernel aggregates use `Indirect` instead of `IndirectAliased` currently in #220177. Will update that PR once this lands.
LINK: https://github.com/llvm/llvm-project/pull/220177#issuecomment-5735833588

https://github.com/llvm/llvm-project/pull/225005