Generate stubs for private function with default arguments as public in interfaces

compiler/testData/codegen/box/jvm8/defaults/allCompatibility/privateFunWithDefaultArg.kt

@@ -0,0 +1,40 @@
+// CHECK_BYTECODE_LISTING
+// !JVM_DEFAULT_MODE: all-compatibility
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// WITH_COROUTINES
+// WITH_RUNTIME
+
+// IGNORE_BACKEND: JVM
+
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+interface Foo {
+
+    fun bar(): String {
+        var result = "fail"
+        builder {
+            result = fooSuspend()
+        }
+        return foo() + result
+
+    }
+
+    private fun foo(s: String = "O"): String {
+        return s
+    }
+
+    private suspend fun fooSuspend(s: String = "K"): String {
+        return s
+    }
+}
+
+fun box(): String {
+    return object : Foo {}.bar()
+}