[PATCH] [lld] [mach-o] Support -l and -syslibroot options

[Tim Northover]

>> Tim , -syslibroot applies to all -L paths - not just the built in ones, or the "system directories".
>
> I don't think it does:

Ah, I see it applies to a basically randomly chosen set of paths. That
we'll almost certainly have to emulate. What fun! I'm rapidly
developing an abiding horror for linkers.

Tim.

http://reviews.llvm.org/D4409