[llvm] [AMDGPU] Emit AMDHSA kernel descriptors to `.amdhsa.kd` section (PR #122930)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> This seems to be an ABI change and likely affect tools. It seems like we would need a new code object version.

Unlikely, all the tools I've looked at did a brute force
```
foreach symbol in symtab:
  if symbol.ends_with(".kd")
     kernel_descriptor
```
Which is unaffected by this patch.

https://github.com/llvm/llvm-project/pull/122930