Merge pull request #7163 from practicalswift/swiftc-28676-anonymous-namespace-findcapturedvars-checktype-swift-type-swift-sourceloc

[swiftc (37 vs. 5451)] Add crasher in swift::ASTVisitor

Author: practicalswift

validation-test/compiler_crashers/28676-anonymous-namespace-findcapturedvars-checktype-swift-type-swift-sourceloc.swift

@@ -0,0 +1,9 @@
+// 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
+let x[{{{{{{{{{{{{{{{{{{{{{{{{struct c{func b(UInt=1 + 1 + 1 + 1 + 1 as?Int){{{{{{{{{{{{struct P