[cxxmodules] Do not generate a rootmap if a module exists.
[cxxmodules] Do not generate a rootmap if a module exists.

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