Migrate test block 30 + corelib portion of block 31 to Dart 2.0.

tests/corelib_2/uri_path_test.dart

Index: tests/corelib_2/uri_path_test.dart
diff --git a/tests/corelib/uri_path_test.dart b/tests/corelib_2/uri_path_test.dart
similarity index 96%
rename from tests/corelib/uri_path_test.dart
rename to tests/corelib_2/uri_path_test.dart
index d46c3a7fcb423b3ab7f54eaae5a00c8a04ed60b1..ce64a6c9a0fc09e576dbc2f09442f6cd8d95d558 100644
--- a/tests/corelib/uri_path_test.dart
+++ b/tests/corelib_2/uri_path_test.dart
@@ -83,13 +83,13 @@ void testPathSegments() {
     }
     unencoded.writeCharCode(i);
   }
-  encoded = encoded.toString();
-  unencoded = unencoded.toString();
-  test(encoded, [unencoded]);
-  test(encoded + "/" + encoded, [unencoded, unencoded]);
+  var encodedStr = encoded.toString();
+  var unencodedStr = unencoded.toString();
+  test(encodedStr, [unencodedStr]);
+  test(encodedStr + "/" + encodedStr, [unencodedStr, unencodedStr]);
 
   Uri uri;
-  List pathSegments = ["xxx", "yyy", "zzz"];
+  var pathSegments = ["xxx", "yyy", "zzz"];
 
   uri = new Uri(pathSegments: pathSegments);
   Expect.equals(3, uri.pathSegments.length);