swift234

[swiftc] Add 💥 case (😢 → 53, 😀 → 5094) triggered in swift::TypeBase::getCanonicalType(…)

Add crash case with stack trace:

```
4  swift           0x000000000111aff4 swift::TypeBase::getCanonicalType() + 20
5  swift           0x0000000001133a7d swift::ConformanceLookupTable::getConformance(swift::NominalTypeDecl*, swift::LazyResolver*, swift::ConformanceLookupTable::ConformanceEntry*) + 301
7  swift           0x0000000001134194 swift::ConformanceLookupTable::lookupConformances(swift::NominalTypeDecl*, swift::DeclContext*, swift::LazyResolver*, swift::ConformanceLookupKind, llvm::SmallVectorImpl<swift::ProtocolDecl*>*, llvm::SmallVectorImpl<swift::ProtocolConformance*>*, llvm::SmallVectorImpl<swift::ConformanceDiagnostic>*) + 692
8  swift           0x00000000011167e4 swift::DeclContext::getLocalConformances(swift::ConformanceLookupKind, llvm::SmallVectorImpl<swift::ConformanceDiagnostic>*, bool) const + 212
9  swift           0x0000000000ef996e swift::TypeChecker::checkConformancesInContext(swift::DeclContext*, swift::IterableDeclContext*) + 334
16 swift           0x0000000000eb25a6 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 150
19 swift           0x0000000000f19c04 swift::TypeChecker::typeCheckClosureBody(swift::ClosureExpr*) + 244
20 swift           0x0000000000f45a2c swift::constraints::ConstraintSystem::applySolution(swift::constraints::Solution&, swift::Expr*, swift::Type, bool, bool, bool) + 876
21 swift           0x0000000000ea0bc1 swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::TypeLoc, swift::ContextualTypePurpose, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::ExprTypeCheckListener*) + 769
23 swift           0x0000000000f19d46 swift::TypeChecker::typeCheckTopLevelCodeDecl(swift::TopLevelCodeDecl*) + 134
24 swift           0x0000000000ed47bd swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int) + 1133
25 swift           0x0000000000c62209 swift::CompilerInstance::performSema() + 3289
27 swift           0x00000000007d89b9 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2857
28 swift           0x00000000007a49f8 main + 2872
Stack dump:
0.	Program arguments: /path/to/swift/bin/swift -frontend -c -primary-file validation-test/compiler_crashers/28337-swift-typebase-getcanonicaltype.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28337-swift-typebase-getcanonicaltype-1d42b8.o
1.	While type-checking expression at [validation-test/compiler_crashers/28337-swift-typebase-getcanonicaltype.swift:9:1 - line:13:17] RangeText="{
2.	While type-checking 'a' at validation-test/compiler_crashers/28337-swift-typebase-getcanonicaltype.swift:10:1
<unknown>:0: error: unable to execute command: Segmentation fault
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```