> How does this get pushed into current?  or should it be sent to tech-kern on 
> the .s v .S thread?
> 
Submit a PR describing the bug along with the patches to fix it. Its also worth
a posting to tech-kern indicating that you have a patch to solve the issue. 
IIRC the feeling on tech kern is that config should deal with .S and .s files
identically and that .S is the correct extension for cpp preprocessed 
assembler.

That way the PR should come to someones attention fairly quickly.

Mike