Added tests on lateinit properties

backend.native/tests/codegen/lateinit/initialized.kt

@@ -0,0 +1,11 @@
+class A {
+    lateinit var s: String
+
+    fun foo() = s
+}
+
+fun main(args: Array<String>) {
+    val a = A()
+    a.s = "zzz"
+    println(a.foo())
+}

backend.native/tests/codegen/lateinit/notInitialized.kt

@@ -0,0 +1,17 @@
+class A {
+    lateinit var s: String
+
+    fun foo() = s
+}
+
+fun main(args: Array<String>) {
+    val a = A()
+    try {
+        println(a.foo())
+    }
+    catch (e: RuntimeException) {
+        println("OK")
+        return
+    }
+    println("Fail")
+}