[lld] r257889 - Reapply r257753 with fix:

[Rafael Espíndola via llvm-commits]

Thanks a lot for implementing this!

> +template <class ELFT>
> +void EhFrameHeader<ELFT>::assignEhFrame(EHOutputSection<ELFT> *Sec) {
> +  if (this->Sec && this->Sec != Sec) {
> +    warning("multiple .eh_frame sections not supported for .eh_frame_hdr");
> +    Live = false;
> +    return;

Can this warning ever fire? If not it should be just an assert.

Cheers,
Rafael