[lld] [lld] Add target support for SystemZ (s390x) (PR #75643)

[Ulrich Weigand via llvm-commits]

uweigand wrote:

Updated the new tests to fix soname-length related errors in the Linux CI.   The Windows CI still fails, but this seems unrelated to my patch?

https://github.com/llvm/llvm-project/pull/75643