Add forwardADSignalTransform pass.

Author: sletz

compiler/propagate/propagate.cpp

@@ -24,6 +24,7 @@
 #include "aterm.hh"
 #include "exception.hh"
 #include "floats.hh"
+#include "forwardADSignalTransform.hh"
 #include "global.hh"
 #include "labels.hh"
 #include "names.hh"
@@ -558,8 +559,7 @@ static siglist realPropagate(Tree slotenv, Tree path, Tree box, const siglist& l
             throw faustexception(error.str());
         }
     } else if (Tree t1; isBoxForwardAD(box, t1)) {
-        // TODO
-        return propagate(slotenv, path, t1, lsig);
+        return generateADSignals(propagate(slotenv, path, t1, lsig));
 
     } else if (Tree t1; isBoxReverseAD(box, t1)) {
         // TODO