[lld] [LLD][SPARC] Implement enough functionality to run non-trivial 64-bit programs (PR #137919)

[Brad Smith via llvm-commits]

brad0 wrote:

> Why not then just land the change as is? Being able to build OpenBSD exclusively with LLVM on sparc64 is a huge step forward,

MaskRay wants unit tests, which is not exactly an unreasonable ask.

https://github.com/llvm/llvm-project/pull/137919