Added tests on interface calls of enum class

backend.native/tests/codegen/enum/interfaceCallWithEntryClass.kt

@@ -0,0 +1,22 @@
+interface A {
+    fun f(): String
+}
+
+enum class Zzz: A {
+    Z1 {
+        override fun f() = "z1"
+    },
+
+    Z2 {
+        override fun f() = "z2"
+    };
+
+    override fun f() = ""
+}
+
+fun main(args: Array<String>) {
+    println(Zzz.Z1.f() + Zzz.Z2.f())
+    val a1: A = Zzz.Z1
+    val a2: A = Zzz.Z2
+    println(a1.f() + a2.f())
+}