Move test files and baselines into subdirectories

Bug Report

VSCode can't really handle the number of files in the tests/cases/compiler directory (5386) or tests/baselines/reference (36655). It makes working with those directories very awkward!

There's plenty of scope for subdirectories, e.g.

anyAndUnknownHaveFalsyComponents.ts
anyAsReturnTypeForNewOnCall.ts
anyDeclare.ts
anyIdenticalToItself.ts
anyIndexedAccessArrayNoException.ts
anyInferenceAnonymousFunctions.ts
anyIsAssignableToObject.ts
anyIsAssignableToVoid.ts
anyMappedTypesError.ts
anyPlusAny1.ts
argsInScope.ts
arguments.ts
argumentsAsPropertyName.ts
argumentsAsPropertyName2.ts
argumentsBindsToFunctionScopeArgumentList.ts
argumentsObjectCreatesRestForJs.ts
argumentsObjectIterator01_ES5.ts
argumentsObjectIterator01_ES6.ts
argumentsObjectIterator02_ES5.ts
argumentsObjectIterator02_ES6.ts
argumentsObjectIterator03_ES5.ts
argumentsObjectIterator03_ES6.ts
argumentsReferenceInConstructor1_Js.ts
argumentsReferenceInConstructor2_Js.ts
argumentsReferenceInConstructor3_Js.ts
argumentsReferenceInConstructor4_Js.ts
argumentsReferenceInConstructor5_Js.ts
argumentsReferenceInConstructor6_Js.ts
argumentsReferenceInConstructor7_Js.ts
argumentsReferenceInMethod1_Js.ts
argumentsReferenceInMethod2_Js.ts
argumentsReferenceInMethod3_Js.ts
argumentsReferenceInMethod4_Js.ts
argumentsReferenceInMethod5_Js.ts
argumentsReferenceInMethod6_Js.ts
argumentsReferenceInMethod7_Js.ts
argumentsUsedInObjectLiteralProperty.ts
arithAssignTyping.ts
arithmeticOnInvalidTypes.ts
arithmeticOnInvalidTypes2.ts
arityErrorRelatedSpanBindingPattern.ts
arrayAssignmentTest1.ts
arrayAssignmentTest2.ts
arrayAssignmentTest3.ts
arrayAssignmentTest4.ts
arrayAssignmentTest5.ts
arrayAssignmentTest6.ts

Could be in these subdirectories

any
arguments
arithmetic
arity
arrayAssignment

I think that would cut down the number of subdirectories to something like 1000 which is much more reasonable. It could be a mostly automated change since the tests are named nicely and in most cases you could just group them by their first word (or maybe even first 1/2 letters?).

🔎 Search Terms

large number many files test cases baselines

Untersuche zunächst die Layout- und Pfadannahmen rund um tests/cases/compiler und tests/baselines/reference, einschließlich der Frage, wie Compiler-Tests ihre Baselines finden. Gruppiere die Testdateien und die zugehörigen Baselines in konsistente Unterverzeichnisse und überprüfe anschließend, dass die Compiler-Testsuite nach dem Verschieben weiterhin Tests entdeckt und mit jeder Baseline übereinstimmt.