Resulting node alias to either branch

        >>> from pythran import passmanager
        >>> pm = passmanager.PassManager('demo')
        >>> module = ast.parse('def foo(a, b, c): return a if c else b')
        >>> result = pm.gather(Aliases, module)
        >>> Aliases.dump(result, filter=ast.IfExp)
        (a if c else b) => ['a', 'b']

def visit_IfExp(self, node):
        '''
        Resulting node alias to either branch

        >>> from pythran import passmanager
        >>> pm = passmanager.PassManager('demo')
        >>> module = ast.parse('def foo(a, b, c): return a if c else b')
        >>> result = pm.gather(Aliases, module)
        >>> Aliases.dump(result, filter=ast.IfExp)
        (a if c else b) => ['a', 'b']
        '''
        self.visit(node.test)
        rec = [self.visit(n) for n in (node.body, node.orelse)]
        return self.add(node, set.union(*rec))