Revert "[modules] Do not offer header files from two different locations."
Revert "[modules] Do not offer header files from two different locations."

This reverts commit 9cc395ab1616337d3dc97054a9811b14fdf60f61.

This was not actually fixing the issue and we have better fix for this issue in
the next commit.

karies/root,olifre/root,karies/root,karies/root,karies/root,olifre/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,olifre/root,karies/root,olifre/root,karies/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,karies/root,karies/root,olifre/root,karies/root,root-mirror/root,karies/root,olifre/root