[K/JS] Fix importing behavior for external interfaces in case of implementing them

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

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.utils.addIfNotNull
 import org.jetbrains.kotlin.utils.addToStdlib.butIf
 import org.jetbrains.kotlin.utils.addToStdlib.runIf
 import org.jetbrains.kotlin.utils.memoryOptimizedMap
+import org.jetbrains.kotlin.utils.memoryOptimizedMapNotNull
 import org.jetbrains.kotlin.utils.toSmartList
 
 class JsClassGenerator(private val irClass: IrClass, val context: JsGenerationContext) {
@@ -537,8 +538,14 @@ private fun IrOverridableDeclaration<*>.overridesExternal(): Boolean {
 
 private val IrClassifierSymbol.isInterface get() = (owner as? IrClass)?.isInterface == true
 
+private fun IrClassSymbol.existsInRuntime(): Boolean {
+    return !owner.isEffectivelyExternal() || !owner.isInterface
+}
+
 class JsIrClassModel(val klass: IrClass) {
-    val superClasses = klass.superTypes.memoryOptimizedMap { it.classifierOrNull as IrClassSymbol }
+    val superClasses = klass.superTypes.memoryOptimizedMapNotNull {
+        (it.classifierOrNull as IrClassSymbol).takeIf(IrClassSymbol::existsInRuntime)
+    }
 
     val preDeclarationBlock = JsCompositeBlock()
     val postDeclarationBlock = JsCompositeBlock()

js/js.translator/testData/box/esModules/jsModule/interfaces.kt

@@ -1,4 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: JS
+// IGNORE_BACKEND: WASM
 // ES_MODULES
 // FILE: bar.kt
 @file:JsModule("./interfaces.mjs")
@@ -26,8 +27,16 @@ external val bar: Bar
 external val baz: Baz
 
 // FILE: test.kt
+import boo.Baz
+
 fun box(): String {
     if (bar.ping() != "ping" || baz.pong() != 194) return "Fail"
 
+    val local = object : Baz {
+        override fun pong(): Int = 322
+    }
+
+    if (local.asDynamic().pong() != 322) return "Fail"
+
     return "OK"
 }