JS backend: _commonFiles/ for common kotlin files in testData/ and every test dir
Create single target for building artifacts to avoid running "dist" twice
Show notification about outdated runtime even in internal mode
Minor, delete outdated assertions in ImplementationBodyCodegen
Minor, remove code duplication in ImplementationBodyCodegen
Minor, remove unreachable code in CodegenContext#intoConstructor
Minor, store closure class name for debugging purposes

Strip package from the name up to the last slash, because slashes are not
allowed in a Name
Minor, add nullability annotations, toString(), remove unused methods
Refactor and rename ExpressionCodegen#generateFromResolvedCall
Minor, add NotNull to JetCoreEnvironment#getConfiguration

 #KT-5460 Fixed
Minor, swap parameters of AnalyzerWithCompilerReport#analyzeAndReport

 #KT-5459 Fixed