This code was introduced back in r178148, a change to introduce
-module-file-info - which still exists & seems like it's still tested (&
this change didn't cause any of those tests to fail).
It doesn't look like this change was necessary there - since it's about
pcm output, whereas -module-file-info looks like it's for pcm /input/.
So I'm not really sure what the original motivation was.
I'm open to ideas though, if it turns out the original change was
necessary/useful.
llvm-svn: 334778