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

まず、tests/cases/compiler と tests/baselines/reference 周辺のレイアウトとパスに関する前提を調べます。これには、コンパイラーテストがどのようにベースラインを見つけるかも含まれます。テストファイルと対応するベースラインを一貫したサブディレクトリにまとめ、その後、移動後もコンパイラーテストスイートがテストを検出し、すべてのベースラインと一致することを確認します。