[clang] [HIP][SPIR-V] Enable -spirv-preserve-auxdata (PR #209520)

[Marcos Maronas via cfe-commits]

maarquitos14 wrote:

> > Function attributes such as convergent are only kept through SPIRV if -spirv-preserve-auxdata is enabled. This is important to keep the translation as accurate as possible.
> 
> `convergent` is just one use case. In reality [NonSemantic.AuxData](https://github.com/KhronosGroup/SPIRV-LLVM-Translator/blob/main/docs/NonSemantic.AuxData.asciidoc) instruction set is used to preserve many other attributes and metadata that do not have representation in SPIR-V.


Indeed, thanks for the clarification. I was using `convergent` only as an example.

https://github.com/llvm/llvm-project/pull/209520