MultifileClassCodegen

- initial implementation
- new Kotlin file kinds + stub builder

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JVMCompilerArguments.java

@@ -69,6 +69,9 @@ public class K2JVMCompilerArguments extends CommonCompilerArguments {
     @Argument(value = "Xno-optimize", description = "Disable optimizations")
     public boolean noOptimize;
 
+    @Argument(value = "Xmultifile-package-facades", description = "Compile package facade classes as multifile classes")
+    public boolean packageFacadesAsMultifileClasses;
+
     @Argument(value = "Xreport-perf", description = "Report detailed performance statistics")
     public boolean reportPerf;