ENH: remove cmSubDirectory from unused files?

Source/cmLocalUnixMakefileGenerator.cxx

@@ -22,7 +22,6 @@
 #include "cmMakeDepend.h"
 #include "cmCacheManager.h"
 #include "cmGeneratedFileStream.h"
-#include "cmSubDirectory.h"
 
 #include <cmsys/RegularExpression.hxx>
 

Source/cmLocalUnixMakefileGenerator.h

@@ -23,7 +23,6 @@ class cmDependInformation;
 class cmMakeDepend;
 class cmTarget;
 class cmSourceFile;
-class cmSubDirectory;
 
 /** \class cmLocalUnixMakefileGenerator
  * \brief Write a LocalUnix makefiles.