fix(KT-43191): add static qualifier for Companion and non-inner objects.

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/export/ExportModelGenerator.kt

@@ -226,7 +226,7 @@ class ExportModelGenerator(
                 type = t,
                 mutable = false,
                 isMember = klass.parent is IrClass,
-                isStatic = true,
+                isStatic = !klass.isInner,
                 isAbstract = false,
                 isProtected = klass.visibility == DescriptorVisibilities.PROTECTED,
                 irGetter = context.mapping.objectToGetInstanceFunction[klass]!!,

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/export/ExportModelToTsDeclarations.kt

@@ -76,7 +76,8 @@ fun ExportedDeclaration.toTypeScript(indent: String, prefix: String = ""): Strin
             isMember -> (if (isAbstract) "abstract " else "") + (if (!mutable) "readonly " else "")
             else -> if (mutable) "let " else "const "
         }
-        "$prefix$visibility$keyword$name: ${type.toTypeScript(indent)};"
+        val possibleStatic = if (isMember && isStatic) "static " else ""
+        "$prefix$visibility$possibleStatic$keyword$name: ${type.toTypeScript(indent)};"
     }
 
     is ExportedClass -> {

js/js.translator/testData/typescript-export/declarations/declarations.d.ts

@@ -51,7 +51,7 @@ declare namespace JS_TESTS {
         function takesO(o: typeof foo.O): number;
         class KT_37829 {
             constructor();
-            readonly Companion: {
+            static readonly Companion: {
                 readonly x: number;
             };
         }

js/js.translator/testData/typescript-export/visibility/visibility.d.ts

@@ -11,9 +11,9 @@ declare namespace JS_TESTS {
         constructor();
         protected readonly protectedVal: number;
         protected protectedFun(): number;
-        protected readonly protectedNestedObject: {
+        protected static readonly protectedNestedObject: {
         };
-        protected readonly Companion: {
+        protected static readonly Companion: {
             readonly companionObjectProp: number;
         };
         readonly publicVal: number;