[lld] r249093 - [elf2] Ignore --{start,end}-group.

[Rafael Espíndola via llvm-commits]

> No, I don't think it does. Building a list of recognized, but ignored
> with warning options makes sense. Silently ignoring things that should
> affect the output in pretty fundamental ways is not a good idea.

Since we are not yet ready for end users it comes down to the
preference of those writing the project on how to get there. So far
every one is cool with this.

Patching implementing those options are welcome.

Cheers,
Rafael