for _, growLen := range []int{0, 100, 1000, 10000, 100000} {
		for _, startLen := range []int{0, 100, 1000, 10000, 100000} {
			xBytes := Repeat(x, startLen)

			buf := NewBuffer(xBytes)
			// If we read, this affects buf.off, which is good to test.
			readBytes, _ := buf.Read(tmp)
			yBytes := Repeat(y, growLen)
			allocs := testing.AllocsPerRun(100, func() {
				buf.Grow(growLen)
				buf.Write(yBytes)
			})

q.x          // (*(*q).T0).x        (*q).x is a valid field selector

p.M0()       // ((*p).T0).M0()      M0 expects *T0 receiver
p.M1()       // ((*p).T1).M1()      M1 expects T1 receiver
p.M2()       // p.M2()              M2 expects *T2 receiver
t.M2()       // (&t).M2()           M2 expects *T2 receiver, see section on Calls
</pre>

<p>
but the following is invalid:
</p>

<pre>

	sb.WriteString("func() ")
	if call.Deferred {
		sb.WriteString("func() ")
	}

	needsUnsafe := false
	result := false
	twoResults := false
	if !call.Deferred {
		// Check whether this call expects two results.
		for _, ref := range f.Ref {
			if ref.Expr != &call.Call.Fun {
				continue
			}
			if ref.Context == ctxCall2 {
				sb.WriteString("(")
				result = true
				twoResults = true
			}

	// TODO(quasilyte): improve error message (#21860).
	VPGATHERQQ X2, (BP)(X20*2), X3  // ERROR "invalid instruction"
	VPGATHERQQ Y2, (BP)(Y20*2), Y3  // ERROR "invalid instruction"
	// YzrMulti4 expects exactly 4 registers referenced by REG_LIST.
	// TODO(quasilyte): improve error message (#21860).
	V4FMADDPS (AX), [Z0-Z4], K1, Z7  // ERROR "invalid instruction"
	V4FMADDPS (AX), [Z0-Z0], K1, Z7  // ERROR "invalid instruction"

q.x          // (*(*q).T0).x        (*q).x is a valid field selector

p.M0()       // ((*p).T0).M0()      M0 expects *T0 receiver
p.M1()       // ((*p).T1).M1()      M1 expects T1 receiver
p.M2()       // p.M2()              M2 expects *T2 receiver
t.M2()       // (&t).M2()           M2 expects *T2 receiver, see section on Calls
</pre>

<p>
but the following is invalid:
</p>

<pre>

			case *ast.GenDecl:
				if isDeprecated(n.Doc) {
					for _, spec := range n.Specs {
						switch spec := spec.(type) {
						case *ast.ValueSpec:
							for _, id := range spec.Names {
								mark(id)
							}
						case *ast.TypeSpec:
							mark(spec.Name)
						}
					}
				}
				return true // look at specs
			case *ast.FuncDecl:
				if isDeprecated(n.Doc) {
					mark(n.Name)