Improve object arrays support. (#182)

Also fix the way how symbol names are being generated. Before arrays2.kt was not linking.

backend.native/tests/runtime/collections/array2.kt

@@ -0,0 +1,7 @@
+fun main(args : Array<String>) {
+    val byteArray = Array<Byte>(5, { i -> (i * 2).toByte() })
+    byteArray.map { println(it) }
+
+    val intArray = Array<Int>(5, { i -> i * 4 })
+    println(intArray.sum())
+}