Build a compilation unit.

def visit_Module(self, node):
        """ Build a compilation unit. """
        # build all types
        deps = sorted(self.dependencies)
        headers = [Include(os.path.join("pythonic", "include",  *t) + ".hpp")
                   for t in deps]
        headers += [Include(os.path.join("pythonic", *t) + ".hpp")
                    for t in deps]

        decls_n_defns = [self.visit(stmt) for stmt in node.body]
        decls, defns = zip(*[s for s in decls_n_defns if s])

        nsbody = [s for ls in decls + defns for s in ls]
        ns = Namespace(pythran_ward + self.passmanager.module_name, nsbody)
        self.result = CompilationUnit(headers + [ns])