Generate default constructor also for private classes when all parameters have default values

#KT-14408 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/DefaultParameterValueSubstitutor.kt

@@ -244,7 +244,7 @@ class DefaultParameterValueSubstitutor(val state: GenerationState) {
 
         if (CodegenBinding.canHaveOuter(state.bindingContext, classDescriptor)) return false
 
-        if (Visibilities.isPrivate(classDescriptor.visibility) || Visibilities.isPrivate(constructorDescriptor.visibility))
+        if (Visibilities.isPrivate(constructorDescriptor.visibility))
             return false
 
         if (constructorDescriptor.valueParameters.isEmpty()) return false

compiler/testData/codegen/box/jvmOverloads/privateClass.kt

@@ -0,0 +1,10 @@
+// IGNORE_BACKEND: JS
+
+// WITH_RUNTIME
+
+private data class C(val status: String = "OK")
+
+fun box(): String {
+    val c = (C::class.java.getConstructor().newInstance())
+    return c.status
+}

compiler/testData/codegen/defaultArguments/reflection/privateClass.kt

@@ -1,4 +1,4 @@
 private class Foo(val a: Int = 1) {}
 
 // CLASS: Foo
-// HAS_DEFAULT_CONSTRUCTOR: false
+// HAS_DEFAULT_CONSTRUCTOR: true

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -8615,6 +8615,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             doTest(fileName);
         }
 
+        @TestMetadata("privateClass.kt")
+        public void testPrivateClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/privateClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("secondaryConstructor.kt")
         public void testSecondaryConstructor() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/secondaryConstructor.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -8615,6 +8615,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("privateClass.kt")
+        public void testPrivateClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/privateClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("secondaryConstructor.kt")
         public void testSecondaryConstructor() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/secondaryConstructor.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -10421,6 +10421,18 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
         }
 
+        @TestMetadata("privateClass.kt")
+        public void testPrivateClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/privateClass.kt");
+            try {
+                doTest(fileName);
+            }
+            catch (Throwable ignore) {
+                return;
+            }
+            throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
+        }
+
         @TestMetadata("secondaryConstructor.kt")
         public void testSecondaryConstructor() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmOverloads/secondaryConstructor.kt");