[swiftc] Add test case for crash triggered in swift::TypeChecker::checkGenericParamList(swift::ArchetypeBuilder*, swift::GenericParamList*, swift::GenericSignature*, bool, swift::GenericTypeResolver*)

Stack trace:

```
4  swift           0x0000000000ed889d swift::TypeChecker::checkGenericParamList(swift::ArchetypeBuilder*, swift::GenericParamList*, swift::GenericSignature*, bool, swift::GenericTypeResolver*) + 93
6  swift           0x0000000000ed8fbe swift::TypeChecker::validateGenericFuncSignature(swift::AbstractFunctionDecl*) + 94
9  swift           0x0000000000e9b621 swift::TypeChecker::validateDecl(swift::ValueDecl*, bool) + 1089
11 swift           0x0000000000e9b621 swift::TypeChecker::validateDecl(swift::ValueDecl*, bool) + 1089
15 swift           0x0000000000f0d0ee swift::TypeChecker::resolveIdentifierType(swift::DeclContext*, swift::IdentTypeRepr*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, bool, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) + 158
17 swift           0x0000000000f0e1c4 swift::TypeChecker::resolveType(swift::TypeRepr*, swift::DeclContext*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) + 164
18 swift           0x0000000000f0cfe0 swift::TypeChecker::validateType(swift::TypeLoc&, swift::DeclContext*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) + 192
19 swift           0x0000000000e9941a swift::TypeChecker::checkInheritanceClause(swift::Decl*, swift::GenericTypeResolver*) + 5370
20 swift           0x0000000000e9b3ef swift::TypeChecker::validateDecl(swift::ValueDecl*, bool) + 527
23 swift           0x0000000000ea0b66 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 150
24 swift           0x0000000000ec3522 swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int) + 1026
25 swift           0x0000000000c580c9 swift::CompilerInstance::performSema() + 3289
27 swift           0x00000000007d7559 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2857
28 swift           0x00000000007a3578 main + 2872
Stack dump:
0.	Program arguments: /path/to/swift/bin/swift -frontend -c -primary-file validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28314-swift-typechecker-checkgenericparamlist-196feb.o
1.	While type-checking 'A' at validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift:10:1
2.	While resolving type e at [validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift:10:9 - line:10:9] RangeText="e"
3.	While type-checking 'e' at validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift:13:1
4.	While type-checking 'e' at validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift:11:1
<unknown>:0: error: unable to execute command: Segmentation fault
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```

Author: practicalswift

validation-test/compiler_crashers/28314-swift-typechecker-checkgenericparamlist.swift

@@ -0,0 +1,13 @@
+// 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
+class A:e
+func e
+where B:e
+typealias e:A