backend: add tests for lambda functions

backend.native/tests/codegen/lambda/lambda9.kt

@@ -0,0 +1,27 @@
+fun main(args : Array<String>) {
+    val lambdas = ArrayList<() -> Unit>()
+
+    for (i in 0..1) {
+        var x = Integer(0)
+        val istr = i.toString()
+
+        lambdas.add {
+            println(istr)
+            println(x.toString())
+            x = x + 1
+        }
+    }
+
+    val lambda1 = lambdas[0]
+    val lambda2 = lambdas[1]
+
+    lambda1()
+    lambda2()
+    lambda1()
+    lambda2()
+}
+
+class Integer(val value: Int) {
+    override fun toString() = value.toString()
+    operator fun plus(other: Int) = Integer(value + other)
+}