Fix Windows paths in complex_reload_test

runtime/observatory/tests/service/complex_reload_test.dart

Index: runtime/observatory/tests/service/complex_reload_test.dart
diff --git a/runtime/observatory/tests/service/complex_reload_test.dart b/runtime/observatory/tests/service/complex_reload_test.dart
index 9876d552c795bda2aeb6283d3a01ba78f42eda21..0b94084d88fd52940c50889b82d917de3b9c2213 100644
--- a/runtime/observatory/tests/service/complex_reload_test.dart
+++ b/runtime/observatory/tests/service/complex_reload_test.dart
@@ -24,7 +24,7 @@ testMain() async {
 }
 
 // Directory that we are running in.
-String directory = Platform.pathSeparator +
+String directory = (Platform.isWindows ? '' : Platform.pathSeparator) +
     Platform.script.pathSegments.sublist(
         0,
         Platform.script.pathSegments.length - 1).join(Platform.pathSeparator);