In the code below, the foo() call is compiled as this:
   foo_foo (_tmp0_ = foo_new (), self->priv->n);
but "self" should actually mean _tmp0_ here.

Compilation of the code below results in:
...
/home/ilya/my/prog/vala/try-array.vala.c:227: error: ‘self’ undeclared (first use in this function)
...
--------------------------
class Foo
{
    int n = 42;
    public void foo(int i = n)
    {
    }
}

void main()
{
    new Foo().foo();
}