[JS IC] fix cross-module nested class references and interface inheritance

^ KT-50528 fixed

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compilerWithIC.kt

@@ -99,7 +99,7 @@ fun compileWithIC(
         module.files.filter { it.fileEntry.name in dirties }
     } ?: module.files
 
-    val ast = transformer.generateBinaryAst(dirtyFiles)
+    val ast = transformer.generateBinaryAst(dirtyFiles, allModules)
 
     ast.entries.forEach { (path, bytes) -> cacheConsumer.commitBinaryAst(path, bytes) }
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformerTmp.kt

@@ -104,14 +104,18 @@ class IrModuleToJsTransformerTmp(
         return CompilerResult(result, dts)
     }
 
-    fun generateBinaryAst(files: Iterable<IrFile>): Map<String, ByteArray> {
+    fun generateBinaryAst(files: Iterable<IrFile>, allModules: Iterable<IrModuleFragment>): Map<String, ByteArray> {
         val exportModelGenerator = ExportModelGenerator(backendContext, generateNamespacesForPackages = true)
 
         val exportData = files.associate { file ->
             file to exportModelGenerator.generateExportWithExternals(file)
         }
 
-        files.forEach { StaticMembersLowering(backendContext).lower(it) }
+        allModules.forEach {
+            it.files.forEach {
+                StaticMembersLowering(backendContext).lower(it)
+            }
+        }
 
         val serializer = JsIrAstSerializer()
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsClassGenerator.kt

@@ -301,7 +301,7 @@ class JsClassGenerator(private val irClass: IrClass, val context: JsGenerationCo
                 ?.let {
                     val implClassDeclaration = it.parent as IrClass
 
-                    if (implClassDeclaration.shouldCopyFrom() && it.body != null) {
+                    if (implClassDeclaration.shouldCopyFrom()) {
                         val reference = context.getNameForStaticDeclaration(it).makeRef()
                         classModel.postDeclarationBlock.statements += jsAssignment(memberRef, reference).makeStmt()
                         if (isFakeOverride) {