[clang] [Clang][Solaris] Support --ld-path in Solaris driver (PR #163000)

[Rainer Orth via cfe-commits]

rorth wrote:

> Can you add a test to clang/test/Driver/solaris-ld.c?
> 
> For Solaris reviews you can tag @rorth

I won't be able to look into this for a while: I'm off to a two-week vacation soon.

However, first things first: which of the non-GNU ld linkers you talk about have actually been ported to Solaris?  I know of none (but haven't looked closely).  AFAIK `lld` isn't among them.

Besides, talking of Illumos there's still [Issue #53919](https://github.com/llvm/llvm-project/issues/53919) which hasn't been addressed by the Illumos community in 3 1/2 years.  If they are finally starting to contribute, it would be good if this could be taken care of.  Not a requirement, but worth considering.

https://github.com/llvm/llvm-project/pull/163000