var p XPos
	if unsafe.Alignof(p) != 4 {
		t.Errorf("alignment = %v; want 4", unsafe.Alignof(p))
	}
	if unsafe.Sizeof(p) != 8 {
		t.Errorf("size = %v; want 8", unsafe.Sizeof(p))
	}
}

func TestSetBase(t *testing.T) {
	var tab PosTable
	b1 := NewFileBase("b1", "b1")
	orig := MakePos(b1, 42, 7)
	xpos := tab.XPos(orig)

	pos := tab.Pos(xpos)
	new := NewInliningBase(b1, 2)
	pos.SetBase(new)