Add enumeration support. (#128)

* Add enumeration support.

* Enum classes lowering.

* merge fix

* merge fix

* used arrayOf from irModule

* changed lowering quant from body to file

* refactoring

* review fixes

* lowering for GET_OBJECT in enums

* enabled tests

* added tests

* moved tests to separate dir

* renamed test files

* moved phase up

* review fixes

* reformat

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

@@ -0,0 +1,24 @@
+enum class Game {
+    ROCK,
+    PAPER,
+    SCISSORS;
+
+    companion object {
+        fun foo() = ROCK
+        val bar = PAPER
+        val values2 = values()
+        val scissors = valueOf("SCISSORS")
+    }
+}
+
+fun box(): String {
+    if (Game.foo() != Game.ROCK) return "Fail 1"
+    if (Game.bar != Game.PAPER) return "Fail 2: ${Game.bar}"
+    if (Game.values().size != 3) return "Fail 3"
+    if (Game.valueOf("SCISSORS") != Game.SCISSORS) return "Fail 4"
+    if (Game.values2.size != 3) return "Fail 5"
+    if (Game.scissors != Game.SCISSORS) return "Fail 6"
+    return "OK"
+}
+
+fun main(args: Array<String>) = println(box())