func chanRType(pos src.XPos, typ *types.Type) ir.Node {
	return kindRType(pos, typ, types.TCHAN)
}

// sliceElemRType asserts that typ is a slice type, and returns an
// expression that yields the *runtime._type value representing typ's
// element type.
func sliceElemRType(pos src.XPos, typ *types.Type) ir.Node {
	base.AssertfAt(typ.IsSlice(), pos, "want slice type, have %v", typ)
	return TypePtrAt(pos, typ.Elem())