Support accessors for private methods for default methods

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

@@ -0,0 +1,24 @@
+// !JVM_DEFAULT_MODE: all-compatibility
+// IGNORE_BACKEND_FIR: JVM_IR
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// WITH_RUNTIME
+
+interface Test {
+    fun test(): String {
+        return privateFun() + privateProp
+    }
+
+    private fun privateFun(): String {
+        return "O"
+    }
+
+    private val privateProp: String
+        get() = "K"
+}
+
+class TestImpl: Test
+
+fun box(): String {
+    return TestImpl().test()
+}