[clang] [llvm] [lld] [mlir] [AMDGPU] Change default AMDHSA Code Object version to 5 (PR #73000)

[David Blaikie via cfe-commits]

dwblaikie wrote:

(patches like this should probably be broken up - test changes to the defaults in lld and llvm for instance don't depend on the change to the clang driver which is the only real semantic change in this patch, right? So probably only change the semantics of clang, and the tests that need to change there - then follow-up with separate commits that update other test coverage to be closer to the current defaults)

https://github.com/llvm/llvm-project/pull/73000