Merge pull request #6557 from practicalswift/swiftc-28598-issatisfied-request

[swiftc (22 vs. 5389)] Add crasher in swift::IterativeTypeChecker::satisfy(...)

Author: practicalswift

validation-test/compiler_crashers/28598-issatisfied-request.swift

@@ -0,0 +1,15 @@
+// This source file is part of the Swift.org open source project
+// Copyright (c) 2014 - 2016 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
+// REQUIRES: asserts
+class a{
+let d= <H
+class B{extension{protocol A{{
+}
+typealias e:a
+func<