Various fixes for HelloWorld. (#27)

backend.native/tests/runtime/basic/hello0.kt

@@ -0,0 +1,4 @@
+// TODO: remove kotlin_native.io once overrides are in place.
+fun main(args : Array<String>) {
+  kotlin_native.io.print("Hello, world!")
+}

backend.native/tests/runtime/basic/hello1-test.c

@@ -0,0 +1,11 @@
+extern void *resolve_symbol(const char*);
+
+int
+run_test() {
+  void (*main)(void*) = resolve_symbol("kfun:main");
+  
+  main((void*)0);
+
+  return 0;
+}
+

backend.native/tests/runtime/basic/hello1.kt

@@ -0,0 +1,4 @@
+// TODO: remove kotlin_native.io once overrides are in place.
+fun main(args : Array<String>) {
+  kotlin_native.io.print(kotlin_native.io.readLine())
+}