Add a test to reveal flaw in call delegation with default implementations in interfaces.

compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgsViaAnonymousObject.kt

@@ -0,0 +1,16 @@
+// !JVM_DEFAULT_MODE: compatibility
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// WITH_RUNTIME
+
+interface A {
+    @JvmDefault
+    fun foo(x: String = "OK"): String {
+        return x
+    }
+}
+
+fun box(): String {
+    val x = object : A {}
+    return x.foo()
+}

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

@@ -14718,6 +14718,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgs.kt");
                 }
 
+                @TestMetadata("defaultArgsViaAnonymousObject.kt")
+                public void testDefaultArgsViaAnonymousObject() throws Exception {
+                    runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgsViaAnonymousObject.kt");
+                }
+
                 @TestMetadata("inheritedJvmDefault.kt")
                 public void testInheritedJvmDefault() throws Exception {
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/inheritedJvmDefault.kt");

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

@@ -14718,6 +14718,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgs.kt");
                 }
 
+                @TestMetadata("defaultArgsViaAnonymousObject.kt")
+                public void testDefaultArgsViaAnonymousObject() throws Exception {
+                    runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgsViaAnonymousObject.kt");
+                }
+
                 @TestMetadata("inheritedJvmDefault.kt")
                 public void testInheritedJvmDefault() throws Exception {
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/inheritedJvmDefault.kt");

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

@@ -13603,6 +13603,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgs.kt");
                 }
 
+                @TestMetadata("defaultArgsViaAnonymousObject.kt")
+                public void testDefaultArgsViaAnonymousObject() throws Exception {
+                    runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/defaultArgsViaAnonymousObject.kt");
+                }
+
                 @TestMetadata("inheritedJvmDefault.kt")
                 public void testInheritedJvmDefault() throws Exception {
                     runTest("compiler/testData/codegen/box/jvm8/defaults/compatibility/inheritedJvmDefault.kt");