[fpc-pascal] Generic + nested type = forward declaration not solved

[robin]

Why does the following fail with:
 test.pp(7,29) Error: Forward declaration not solved "constructor 
TVector$LongInt.TIter.Create;"

program Test;
{$mode objfpc}{$H+}
type
    generic TVector<T> = object
        type
            TIter = object
                constructor Create;
            end;
    end;
    TIntVector = specialize TVector<Integer>;
constructor TVector.TIter.Create; begin end;
begin
end.