Local declarations and initializers fixes (#222)

* captured values are stored in corresponding fields before call to super constructor

* preserving the order of initializers

* tests

* refactoring

* - test fix
- workaround of IR bug

* refactoring

* review fix

backend.native/tests/codegen/initializers/correctOrder1.kt

@@ -0,0 +1,13 @@
+class Test {
+    val x: Int
+
+    init {
+        x = 42
+    }
+
+    val y = x
+}
+
+fun main(args: Array<String>) {
+    println(Test().y)
+}

backend.native/tests/codegen/initializers/correctOrder2.kt

@@ -0,0 +1,13 @@
+class Test {
+    val x: Int
+
+    val y = 42
+
+    init {
+        x = y
+    }
+}
+
+fun main(args: Array<String>) {
+    println(Test().x)
+}