Merge pull request #5319 from practicalswift/swiftc-28440-swift-typechecker-resolveidentifiertype

[swiftc (77 vs. 5175)] Add crasher in swift::TypeChecker::resolveIdentifierType(...)

Author: practicalswift

validation-test/compiler_crashers/28440-swift-typechecker-resolveidentifiertype.swift

@@ -0,0 +1,10 @@
+// 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 http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+
+// RUN: not --crash %target-swift-frontend %s -parse
+// REQUIRES: asserts
+typealias f=(let a{let a={var:f.t