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

[Ulrich Weigand via llvm-commits]

uweigand wrote:

> It looks like that `__KSYM_REF()` is indeed asking for an absolute address that is incompatible with a `-pie` executable.

Well, this just emit a ".quad symbol", which should certainly be supported with `-pie`.   My understanding is that this should simply leave a `R_390_64` as dynamic relocation, to be resolved at load time.

I suspect the reason lld doesn't do that is because the section may not be writable, and so it thinks it cannot put dynamic relocations there.  Does `-z notext` help?


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