[swiftc] Add 💥 case (😢 → 44, 😀 → 5089) triggered in swift::TypeBase::getString(…) const

Add crash case with stack trace:

```
swift: /path/to/swift/lib/AST/ASTPrinter.cpp:4061: void (anonymous namespace)::TypePrinter::visitArchetypeType(swift::ArchetypeType *): Assertion `GTD && GTD->isProtocolSelf()' failed.
12 swift           0x0000000001025430 swift::TypeBase::getString(swift::PrintOptions const&) const + 160
14 swift           0x00000000010c6e1b swift::DiagnosticEngine::emitDiagnostic(swift::Diagnostic const&) + 2923
15 swift           0x00000000010c608f swift::DiagnosticEngine::flushActiveDiagnostic() + 319
19 swift           0x0000000000ea1586 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 150
22 swift           0x0000000000f08704 swift::TypeChecker::typeCheckClosureBody(swift::ClosureExpr*) + 244
23 swift           0x0000000000f3444c swift::constraints::ConstraintSystem::applySolution(swift::constraints::Solution&, swift::Expr*, swift::Type, bool, bool, bool) + 876
24 swift           0x0000000000e8fba1 swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::TypeLoc, swift::ContextualTypePurpose, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::ExprTypeCheckListener*) + 769
27 swift           0x0000000000f0738a swift::TypeChecker::typeCheckFunctionBodyUntil(swift::FuncDecl*, swift::SourceLoc) + 346
28 swift           0x0000000000f071ee swift::TypeChecker::typeCheckAbstractFunctionBodyUntil(swift::AbstractFunctionDecl*, swift::SourceLoc) + 46
29 swift           0x0000000000f07db3 swift::TypeChecker::typeCheckAbstractFunctionBody(swift::AbstractFunctionDecl*) + 179
31 swift           0x0000000000ec3831 swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int) + 1281
32 swift           0x0000000000c59299 swift::CompilerInstance::performSema() + 3289
34 swift           0x00000000007d72b9 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2857
35 swift           0x00000000007a32c8 main + 2872
Stack dump:
0.	Program arguments: /path/to/swift/bin/swift -frontend -c -primary-file validation-test/compiler_crashers/28323-swift-typebase-getstring.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28323-swift-typebase-getstring-f72c53.o
1.	While type-checking 'a' at validation-test/compiler_crashers/28323-swift-typebase-getstring.swift:10:37
2.	While type-checking expression at [validation-test/compiler_crashers/28323-swift-typebase-getstring.swift:10:44 - line:10:52] RangeText="{enum B:e"
3.	While type-checking 'B' at validation-test/compiler_crashers/28323-swift-typebase-getstring.swift:10:45
<unknown>:0: error: unable to execute command: Aborted
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```

Author: practicalswift

validation-test/compiler_crashers/28323-swift-typebase-getstring.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
+{protocol e{typealias e enum b{case func a{{enum B:e