How to run lit tests on Mac OSX without gcc?

[Thomas Mader via digitalmars-d-ldc]

On Sunday, 3 September 2017 at 10:46:23 UTC, Nicholas Wilson 
wrote:
>> There is no gcc on this system. Is it possible to get the lit 
>> tests running without gcc as linker?
>> Everything else is built and run with clang.
>
> ldc has a -gcc flag to override the gcc used for linking, it is 
> hidden which is why you didn't find it.
>
> ldc -gcc=/path/to/clang <rest of args>

Yes I found that one already somewhere in the forums but it 
wasn't helping in this case since ldc is called from the lit 
tests script and the linker needs to be detected via the 
environment.