Don't generate delegation to java default methods

#KT-15226  Fixed

compiler/testData/codegen/java8/box/delegationBy/simple.kt

@@ -0,0 +1,21 @@
+// FILE: Base.java
+
+public interface Base {
+    String getValue();
+
+    default String test() {
+        return getValue();
+    }
+}
+
+// FILE: main.kt
+class Fail : Base {
+    override fun getValue() = "Fail"
+}
+
+fun box(): String {
+    val z = object : Base by Fail() {
+        override fun getValue() = "OK"
+    }
+    return z.test()
+}