Fix: using statement in another namespace that pointer to type alias

[HungMingWu]

Test case:

A : namespace = {
        t1: type == int;
}

B : namespace = {
        using A::t1;
}

int main()
{
        return 0;
}

[hsutter]

Thanks for your pull request! It looks like this may be your first contribution to cppfront. I've emailed you the Contributor License Agreement (CLA), and once it's signed I can look at your pull request. Thanks again for your contribution.

[hsutter]

Thanks! I agree that the above example isn't handled correctly so there is a bug, but when I tried this PR it fixes that example but breaks others and doesn't pass regression tests.

Here is an example that no longer works with this PR:

A : namespace = {
    test: <T> type == std::vector<T>;
}

which in this PR lowers to:

namespace A {
    template<typename T> using test = std::vector<T>;
}

namespace A {
    template<typename T> 
}

namespace A {

}

I didn't see a quick way to resolve the problem myself just now, but if you want to keep trying I'll review this PR again if you have an update that passes regression tests. Thanks!

[hsutter]

Hi! I'm sorry I can't get this branch to self-build... rebuilding reflect.h2 and cppregex.h2 generates code that doesn't build. I haven't looked to see why (sorry).

For now I'm going to close this, but if you want to try again please reopen a new PR. Thanks again, I do appreciate your interest and contribution!