[svn r354] Fix the regressions between [346] and [353] by making constructors and destructors outside classes fatal errors. Fix tests makefile and add minimize to gc.d.

module bug8;

void main()
{
    s = newS();
}

S* s;

struct S
{
    int i;
}

S* newS()
{
    auto tmp = new S;
    tmp.i = 4;
    return tmp;
}