In the lic code printer, invent an alias to every type, so that node

profiles constain only named types.

Typically, instead of printing:

           node toto(x: int ^ 4) ...

print something like :

           type int4 = int ^ 4
           node toto(x: int4) ...

Moreover, in  order to  avoid name clashes,  we prefix all  user name
type by "_".