Merge pull request #6556 from practicalswift/swiftc-28597-first-char-of-sub-string-may-not-be-a-digit

[swiftc (21 vs. 5389)] Add crasher in swift::NewMangling::Mangler::appendIdentifier(...)

Author: practicalswift

validation-test/compiler_crashers/28597-first-char-of-sub-string-may-not-be-a-digit.swift

@@ -0,0 +1,11 @@
+// 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
+// non-fuzz
+let β1=0