swift234

[swiftc] Add 💥 case (😢 → 47, 😀 → 5089) triggered in swift::TypeBase::getMemberSubstitutions(…)

Add crash case with stack trace:

```
4  swift           0x0000000001112d47 swift::TypeBase::getMemberSubstitutions(swift::DeclContext const*) + 23
5  swift           0x0000000001113186 swift::TypeBase::getTypeOfMember(swift::ModuleDecl*, swift::Type, swift::DeclContext const*) + 54
7  swift           0x0000000000ea2db9 swift::TypeChecker::checkDeclCircularity(swift::NominalTypeDecl*) + 393
13 swift           0x0000000000ea1586 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 150
16 swift           0x0000000000f08704 swift::TypeChecker::typeCheckClosureBody(swift::ClosureExpr*) + 244
17 swift           0x0000000000f3444c swift::constraints::ConstraintSystem::applySolution(swift::constraints::Solution&, swift::Expr*, swift::Type, bool, bool, bool) + 876
18 swift           0x0000000000e8fba1 swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::TypeLoc, swift::ContextualTypePurpose, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::ExprTypeCheckListener*) + 769
21 swift           0x0000000000f077dd swift::TypeChecker::typeCheckConstructorBodyUntil(swift::ConstructorDecl*, swift::SourceLoc) + 845
22 swift           0x0000000000f071e2 swift::TypeChecker::typeCheckAbstractFunctionBodyUntil(swift::AbstractFunctionDecl*, swift::SourceLoc) + 34
23 swift           0x0000000000f07db3 swift::TypeChecker::typeCheckAbstractFunctionBody(swift::AbstractFunctionDecl*) + 179
25 swift           0x0000000000ec3831 swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int) + 1281
26 swift           0x0000000000c59299 swift::CompilerInstance::performSema() + 3289
28 swift           0x00000000007d72b9 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2857
29 swift           0x00000000007a32c8 main + 2872
Stack dump:
0.	Program arguments: /path/to/swift/bin/swift -frontend -c -primary-file validation-test/compiler_crashers/28326-swift-typebase-getmembersubstitutions.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28326-swift-typebase-getmembersubstitutions-44b09e.o
1.	While type-checking 'init' at validation-test/compiler_crashers/28326-swift-typebase-getmembersubstitutions.swift:9:9
2.	While type-checking expression at [validation-test/compiler_crashers/28326-swift-typebase-getmembersubstitutions.swift:9:16 - line:9:53] RangeText="{extension{{}protocol a{struct B{let a"
3.	While type-checking declaration 0x6103c20 at validation-test/compiler_crashers/28326-swift-typebase-getmembersubstitutions.swift:9:17
<unknown>:0: error: unable to execute command: Segmentation fault
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```