b.WriteString("z")
	if err := b.Flush(); err != nil {
		t.Error("WriteString", err)
	}
	s := "01234567890abcdefghijklmnopqrstuvwxyz"
	if buf.String() != s {
		t.Errorf("WriteString wants %q gets %q", s, buf.String())
	}
}

func TestWriteStringStringWriter(t *testing.T) {
	const BufSize = 8
	{
		tw := &teststringwriter{}
		b := NewWriterSize(tw, BufSize)
		b.WriteString("1234")

			t.Go = c.goVoidPtr
			t.C.Set("void*")
			dq := dt.Type
			for {
				if d, ok := dq.(*dwarf.QualType); ok {
					t.C.Set(d.Qual + " " + t.C.String())
					dq = d.Type
				} else {
					break
				}
			}
			break
		}

		// Placeholder initialization; completed in FinishType.
		t.Go = &ast.StarExpr{}
		t.C.Set("<incomplete>*")
		key := dt.Type.String()

	//      this is OK since r0 == $0, but the latter is preferred.
	ADD $0, R6, R5             	// 7ca60214

        //TODO: the assembler rewrites these into ADDIS $19, R5, Rx and ADD $-10617, Rx, Rx, but the test only sees the first ADDIS
	ADD $1234567, R5                // 3ca50013 or 0600001238a5d687
	ADD $1234567, R5, R6            // 3cc50013 or 0600001238c5d687

	ADDEX R3, R5, $3, R6            // 7cc32f54