ByteType = defBasic(TUINT8, BuiltinPkg, "byte")
	RuneType = defBasic(TINT32, BuiltinPkg, "rune")

	// error type
	DeferCheckSize()
	ErrorType = defBasic(TFORW, BuiltinPkg, "error")
	ErrorType.SetUnderlying(makeErrorInterface())
	ResumeCheckSize()

	// comparable type (interface)
	DeferCheckSize()
	ComparableType = defBasic(TFORW, BuiltinPkg, "comparable")
	ComparableType.SetUnderlying(makeComparableInterface())

		return
	}

	if t.widthCalculated() {
		return
	}

	if CalcSizeDisabled {
		base.Fatalf("width not calculated: %v", t)
	}

	// defer CheckSize calls until after we're done
	DeferCheckSize()

	lno := base.Pos
	if pos := t.Pos(); pos.IsKnown() {
		base.Pos = pos
	}

	t.width = -2
	t.align = 0  // 0 means use t.Width, below
	t.alg = AMEM // default
	// default t.ptrBytes is 0.