Merge pull request #6597 from practicalswift/swiftc-28615-swift-constraints-constraintgraph-bindtypevariable-swift-typevariabletype-swift

[swiftc (38 vs. 5390)] Add crasher in swift::constraints::ConstraintGraph::bindTypeVariable

Author: practicalswift

validation-test/compiler_crashers/28615-swift-constraints-constraintgraph-bindtypevariable-swift-typevariabletype-swift.swift

@@ -0,0 +1,9 @@
+// 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
+print(_===#keyPath(t>c