Merge pull request #12290 from practicalswift/swiftc-28852-swift-genericsignaturebuilder-addrequirement-swift-requirementrepr-const-swift-g

[swiftc (58 vs. 5600)] Add crasher in swift::GenericSignatureBuilder::addRequirement

Author: practicalswift

validation-test/compiler_crashers/28852-swift-genericsignaturebuilder-addrequirement-swift-requirementrepr-const-swift-g.swift

@@ -0,0 +1,12 @@
+// 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
+extension P{}
+protocol P{{}typealias e:A
+protocol A{{}typealias e where f=a
+{}class a