Merge pull request #6591 from practicalswift/swiftc-28609-unreachable-executed-at-swift-lib-sema-csapply-cpp-5859

[swiftc (32 vs. 5390)] Add crasher in swift::ASTVisitor

Author: practicalswift

validation-test/compiler_crashers/28609-unreachable-executed-at-swift-lib-sema-csapply-cpp-5859.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
+_{d->Void!in{