JS: allow to omit delegated constructor call for external classes in common FE. Prohibit delegated constructor call for external classes in JS FE.

compiler/frontend/src/org/jetbrains/kotlin/resolve/BodyResolver.java

@@ -169,8 +169,8 @@ public class BodyResolver {
             @NotNull KtSecondaryConstructor constructor,
             @NotNull ClassConstructorDescriptor descriptor
     ) {
-        if (descriptor.isHeader()) {
-            // For header classes, we do not resolve constructor delegation calls because they are prohibited
+        if (descriptor.isHeader() || DescriptorUtils.isEffectivelyExternal(descriptor)) {
+            // For header and external classes, we do not resolve constructor delegation calls because they are prohibited
             return DataFlowInfo.Companion.getEMPTY();
         }
 
@@ -367,7 +367,7 @@ public class BodyResolver {
                     descriptor.getUnsubstitutedPrimaryConstructor() != null &&
                     superClass.getKind() != ClassKind.INTERFACE &&
                     !superClass.getConstructors().isEmpty() &&
-                    !descriptor.isHeader() &&
+                    !descriptor.isHeader() && !DescriptorUtils.isEffectivelyExternal(descriptor) &&
                     !ErrorUtils.isError(superClass)
                 ) {
                     trace.report(SUPERTYPE_NOT_INITIALIZED.on(specifier));