BC native tests port to Konan's TestRunner

backend.native/tests/codegen/function/sum_3const.kt

@@ -1,6 +1,10 @@
+package codegen.function.sum_3const
+
+import kotlin.test.*
+
 fun sum3():Int = sum(1, 2, 33)
 fun sum(a:Int, b:Int, c:Int): Int = a + b + c
 
-fun main(args: Array<String>) {
+@Test fun runTest() {
     if (sum3() != 36) throw Error()
 }