BC native tests port to Konan's TestRunner

backend.native/tests/lower/tailrec.kt

@@ -1,4 +1,8 @@
-fun main(args: Array<String>) {
+package lower.tailrec
+
+import kotlin.test.*
+
+@Test fun runTest() {
     println(add(5, 7))
     println(add(100000000, 0))
 

backend.native/tests/lower/vararg.kt

@@ -1,6 +1,10 @@
+package lower.vararg
+
+import kotlin.test.*
+
 fun foo(vararg x: Any?) {}
 fun bar() = foo()
 
-fun main(arg:Array<String>) {
+@Test fun runTest() {
   bar()
 }

backend.native/tests/lower/vararg_of_literals.kt

@@ -1,4 +1,8 @@
-fun main(args: Array<String>) {
+package lower.vararg_of_literals
+
+import kotlin.test.*
+
+@Test fun runTest() {
     foo()
     foo()
 }