Froze enums on creation + tests

backend.native/tests/build.gradle

@@ -704,6 +704,16 @@ task enum_nested(type: RunKonanTest) {
     source = "codegen/enum/nested.kt"
 }
 
+task enum_isFrozen(type: RunKonanTest) {
+    goldValue = "true\n"
+    source = "codegen/enum/isFrozen.kt"
+}
+
+task enum_loop(type: RunKonanTest) {
+    goldValue = "Z\nZ\n"
+    source = "codegen/enum/loop.kt"
+}
+
 task mangling(type: LinkKonanTest) {
     goldValue = 
         "Int direct [1, 2, 3, 4]\n" +

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

@@ -0,0 +1,13 @@
+package codegen.enum.isFrozen
+
+import kotlin.test.*
+import konan.worker.*
+
+enum class Zzz(val zzz: String) {
+    Z1("z1"),
+    Z2("z2")
+}
+
+@Test fun runTest() {
+    println(Zzz.Z1.isFrozen)
+}

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

@@ -0,0 +1,15 @@
+package codegen.enum.loop
+
+import kotlin.test.*
+
+enum class Zzz {
+    Z {
+        init {
+            println(Z.name)
+        }
+    }
+}
+
+@Test fun runTest() {
+    println(Zzz.Z)
+}