28828-unreachable-executed-at-swift-lib-ast-type-cpp-3237.swift

// This source file is part of the Swift.org open source project
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors

// RUN: not --crash %target-swift-frontend %s -emit-ir
class a<a{class a{extension{protocol P{class a:a{func a:Self.a