swift234

[swiftc] Add 💥 case (😢 → 54, 😀 → 5094) triggered in swift::GenericSignature::getSubstitutionMap(…)

Add crash case with stack trace:

```
swift: /path/to/swift/lib/AST/GenericSignature.cpp:413: TypeSubstitutionMap swift::GenericSignature::getSubstitutionMap(ArrayRef<swift::Substitution>) const: Assertion `args.empty() && "did not use all substitutions?!"' failed.
8  swift           0x00000000010e5f63 swift::GenericSignature::getSubstitutionMap(llvm::ArrayRef<swift::Substitution>) const + 659
9  swift           0x0000000000f32442 swift::createDesignatedInitOverride(swift::TypeChecker&, swift::ClassDecl*, swift::ConstructorDecl*, swift::DesignatedInitKind) + 338
10 swift           0x0000000000eb8833 swift::TypeChecker::addImplicitConstructors(swift::NominalTypeDecl*) + 3187
19 swift           0x0000000000eb25a6 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 150
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/28338-swift-genericsignature-getsubstitutionmap.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28338-swift-genericsignature-getsubstitutionmap-62e861.o
1.	While type-checking 'A' at validation-test/compiler_crashers/28338-swift-genericsignature-getsubstitutionmap.swift:11:1
<unknown>:0: error: unable to execute command: Aborted
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```