[lld] ELF,SystemZ: Don't sort relocations for TLS GD/LD optimization; support CREL (PR #149640)

[Ulrich Weigand via llvm-commits]

https://github.com/uweigand commented:

I guess I'd be OK with this.  It would still be nicer if this false dependency could be avoided.  Not sure what CREL has to do with relocation sorting: is the problem indeed the swap of these two TLS-related relocs, or is the problem that generic sorting also introduces other changes?  If the latter, maybe we could just swap those TLS relocs instead of a generic sorting path?  Or simply allow a more generic relocation-skipping mechanism that allows skipping the reloc *before* a TLS reloc as well as the reloc after the TLS reloc?

https://github.com/llvm/llvm-project/pull/149640