r.shadowedPredecl = make(map[string]bool)
			}
			r.shadowedPredecl[name] = true
		}
	}
	return false
}

// copyConstType returns a copy of typ with position pos.
// typ must be a valid constant type.
// In practice, only (possibly qualified) identifiers are possible.
func copyConstType(typ ast.Expr, pos token.Pos) ast.Expr {
	switch typ := typ.(type) {
	case *ast.Ident:
		return &ast.Ident{Name: typ.Name, NamePos: pos}