[clang] [clang] Add GCC-compatible code model names for sparc64 (PR #79485)

[Fangrui Song via cfe-commits]

MaskRay wrote:

> > I'd run 2-stage builds/tests (either with the existing machinery or by building LLVM twice explicitly: once with an external compiler and then again with the just-built one).
> 
> It does seem that at least when it comes to LLVM itself, 2-stage build/tests works okay under all of the supported code models...

Can you edit the description (first comment) to include your testing?

https://github.com/llvm/llvm-project/pull/79485