Fix for KT-3546: Exception when delegating to ArrayList

#KT-3546 Fixed

compiler/testData/codegen/box/classes/kt3546.kt

@@ -0,0 +1,25 @@
+trait A {
+    fun test(): String
+}
+
+trait B {
+    fun test(): String
+}
+
+trait C: A, B
+
+class Z(val param: String): C {
+
+    override fun test(): String {
+        return param
+    }
+}
+
+public class MyClass(val value : C) : C by value {
+
+}
+
+fun box(): String {
+    val s = MyClass(Z("OK"))
+    return s.test()
+}