[clang] [Driver][Sparc] Default to -mcpu=v9 for 32-bit Linux/sparc64 (PR #109278)

[Fangrui Song via cfe-commits]

MaskRay wrote:

> > Just to be certain: the revised version of the patch is ok to commit?
> 
> I think it would be good to get an ACK from at least one of the SPARC Leon maintainers.
> 
> CC @andreas-gaisler

Thanks for informing the maintainer. Note: this is done as a courtesy. When we bump a setting -mcpu= for good reasons, we do not add exception code like `!isVendorA() && !isVendorB()`. clangDriver is moving out of business to hard code such vendor details and requires adoption of Clang configuration files.

https://github.com/llvm/llvm-project/pull/109278