[swiftc (55 vs. 5458)] Add crasher in swift::TypeChecker::resolveTypeInContext

Add test case for crash triggered in `swift::TypeChecker::resolveTypeInContext`.

Current number of unresolved compiler crashers: 55 (5458 resolved)

/cc @slavapestov - just wanted to let you know that this crasher caused an assertion failure for the assertion `false && "Should have found context by now"` added on 2016-12-06 by you in commit fdaa886 :-)

Assertion failure in [`lib/Sema/TypeCheckType.cpp (line 358)`](https://github.com/apple/swift/blob/d352652a72c73157d94e5fdc0fb477453da41c94/lib/Sema/TypeCheckType.cpp#L358):

```
Assertion `false && "Should have found context by now"' failed.

When executing: std::tuple<DeclContext *, NominalTypeDecl *, bool> findDeclContextForType(swift::TypeChecker &, swift::TypeDecl *, swift::DeclContext *, TypeResolutionOptions)
```

Assertion context:

```c++
    // or associated type from a context outside a ProtocolDecl.
    if (isa<ProtocolDecl>(parentDC) && isa<AbstractTypeParamDecl>(typeDecl))
      return std::make_tuple(nullptr, nullptr, false);
  }

  assert(false && "Should have found context by now");
  return std::make_tuple(nullptr, nullptr, false);
}

Type TypeChecker::resolveTypeInContext(
       TypeDecl *typeDecl,
```
Stack trace:

```
0 0x0000000003934028 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/path/to/swift/bin/swift+0x3934028)
1 0x0000000003934766 SignalHandler(int) (/path/to/swift/bin/swift+0x3934766)
2 0x00007fa2f0e883e0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x113e0)
3 0x00007fa2ef5e6428 gsignal /build/glibc-Qz8a69/glibc-2.23/signal/../sysdeps/unix/sysv/linux/raise.c:54:0
4 0x00007fa2ef5e802a abort /build/glibc-Qz8a69/glibc-2.23/stdlib/abort.c:91:0
5 0x00007fa2ef5debd7 __assert_fail_base /build/glibc-Qz8a69/glibc-2.23/assert/assert.c:92:0
6 0x00007fa2ef5dec82 (/lib/x86_64-linux-gnu/libc.so.6+0x2dc82)
7 0x00000000011ea497 swift::TypeChecker::resolveTypeInContext(swift::TypeDecl*, swift::DeclContext*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, bool, swift::GenericTypeResolver*) (/path/to/swift/bin/swift+0x11ea497)
8 0x00000000011f1d58 resolveTypeDecl(swift::TypeChecker&, swift::TypeDecl*, swift::SourceLoc, swift::DeclContext*, swift::GenericIdentTypeRepr*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11f1d58)
9 0x00000000011f1994 resolveTopLevelIdentTypeComponent(swift::TypeChecker&, swift::DeclContext*, swift::ComponentIdentTypeRepr*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, bool, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11f1994)
10 0x00000000011ec1eb resolveIdentTypeComponent(swift::TypeChecker&, swift::DeclContext*, llvm::ArrayRef<swift::ComponentIdentTypeRepr*>, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, bool, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11ec1eb)
11 0x00000000011ebc13 swift::TypeChecker::resolveIdentifierType(swift::DeclContext*, swift::IdentTypeRepr*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, bool, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11ebc13)
12 0x00000000011ecc47 (anonymous namespace)::TypeResolver::resolveType(swift::TypeRepr*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>) (/path/to/swift/bin/swift+0x11ecc47)
13 0x00000000011ecb4c swift::TypeChecker::resolveType(swift::TypeRepr*, swift::DeclContext*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11ecb4c)
14 0x00000000011eb27a swift::TypeChecker::validateType(swift::TypeLoc&, swift::DeclContext*, swift::OptionSet<swift::TypeResolutionFlags, unsigned int>, swift::GenericTypeResolver*, llvm::function_ref<bool (swift::TypeCheckRequest)>*) (/path/to/swift/bin/swift+0x11eb27a)
15 0x0000000001360753 swift::IterativeTypeChecker::processResolveInheritedClauseEntry(std::pair<llvm::PointerUnion<swift::TypeDecl*, swift::ExtensionDecl*>, unsigned int>, llvm::function_ref<bool (swift::TypeCheckRequest)>) (/path/to/swift/bin/swift+0x1360753)
16 0x0000000001356516 swift::IterativeTypeChecker::satisfy(swift::TypeCheckRequest) (/path/to/swift/bin/swift+0x1356516)
17 0x00000000013565db swift::IterativeTypeChecker::satisfy(swift::TypeCheckRequest) (/path/to/swift/bin/swift+0x13565db)
18 0x00000000012dcd00 swift::TypeChecker::resolveInheritedProtocols(swift::ProtocolDecl*) (/path/to/swift/bin/swift+0x12dcd00)
19 0x000000000143d38d swift::GenericSignatureBuilder::addConformanceRequirement(swift::GenericSignatureBuilder::PotentialArchetype*, swift::ProtocolDecl*, swift::RequirementSource const*, llvm::SmallPtrSetImpl<swift::ProtocolDecl*>&) (/path/to/swift/bin/swift+0x143d38d)
20 0x000000000144893d bool llvm::function_ref<bool (swift::Type, swift::TypeRepr const*)>::callback_fn<swift::GenericSignatureBuilder::addInheritedRequirements(swift::TypeDecl*, swift::GenericSignatureBuilder::PotentialArchetype*, swift::RequirementSource const*, llvm::SmallPtrSetImpl<swift::ProtocolDecl*>&)::$_14>(long, swift::Type, swift::TypeRepr const*) (/path/to/swift/bin/swift+0x144893d)
21 0x000000000144391d std::_Function_handler<void (swift::Type, swift::TypeRepr const*), visitInherited(llvm::ArrayRef<swift::TypeLoc>, llvm::function_ref<bool (swift::Type, swift::TypeRepr const*)>)::$_28>::_M_invoke(std::_Any_data const&, swift::Type&&, swift::TypeRepr const*&&) (/path/to/swift/bin/swift+0x144391d)
22 0x000000000143d0cf swift::GenericSignatureBuilder::addInheritedRequirements(swift::TypeDecl*, swift::GenericSignatureBuilder::PotentialArchetype*, swift::RequirementSource const*, llvm::SmallPtrSetImpl<swift::ProtocolDecl*>&) (/path/to/swift/bin/swift+0x143d0cf)
23 0x000000000143cf30 swift::GenericSignatureBuilder::addGenericParameterRequirements(swift::GenericTypeParamDecl*) (/path/to/swift/bin/swift+0x143cf30)
24 0x000000000130ba65 swift::TypeChecker::checkGenericParamList(swift::GenericSignatureBuilder*, swift::GenericParamList*, swift::GenericSignature*, swift::GenericTypeResolver*) (/path/to/swift/bin/swift+0x130ba65)
25 0x000000000130e8a2 swift::TypeChecker::checkGenericEnvironment(swift::GenericParamList*, swift::DeclContext*, swift::GenericSignature*, bool, llvm::function_ref<void (swift::GenericSignatureBuilder&)>) (/path/to/swift/bin/swift+0x130e8a2)
26 0x000000000130ecc9 swift::TypeChecker::validateGenericTypeSignature(swift::GenericTypeDecl*) (/path/to/swift/bin/swift+0x130ecc9)
27 0x00000000012dfc95 swift::TypeChecker::validateDecl(swift::ValueDecl*) (/path/to/swift/bin/swift+0x12dfc95)
28 0x00000000012f38e7 (anonymous namespace)::DeclChecker::visitProtocolDecl(swift::ProtocolDecl*) (/path/to/swift/bin/swift+0x12f38e7)
29 0x00000000012e56d1 (anonymous namespace)::DeclChecker::visit(swift::Decl*) (/path/to/swift/bin/swift+0x12e56d1)
30 0x00000000012f2d3b (anonymous namespace)::DeclChecker::visitClassDecl(swift::ClassDecl*) (/path/to/swift/bin/swift+0x12f2d3b)
31 0x00000000012e5585 (anonymous namespace)::DeclChecker::visit(swift::Decl*) (/path/to/swift/bin/swift+0x12e5585)
32 0x00000000012e54b3 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) (/path/to/swift/bin/swift+0x12e54b3)
33 0x00000000011fa4f5 swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int) (/path/to/swift/bin/swift+0x11fa4f5)
34 0x0000000000f38446 swift::CompilerInstance::performSema() (/path/to/swift/bin/swift+0xf38446)
35 0x00000000004a5266 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) (/path/to/swift/bin/swift+0x4a5266)
36 0x0000000000464347 main (/path/to/swift/bin/swift+0x464347)
37 0x00007fa2ef5d1830 __libc_start_main /build/glibc-Qz8a69/glibc-2.23/csu/../csu/libc-start.c:325:0
38 0x00000000004619e9 _start (/path/to/swift/bin/swift+0x4619e9)
```

Author: practicalswift

validation-test/compiler_crashers/28701-false-should-have-found-context-by-now.swift

@@ -0,0 +1,10 @@
+// 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
+
+// REQUIRES: asserts
+// RUN: not --crash %target-swift-frontend %s -emit-ir
+protocol P{class a}class C:P{protocol A:a