Use patching for dart:io.

tests/standalone/io/http_date_test.dart

Index: tests/standalone/io/http_date_test.dart
diff --git a/tests/standalone/io/http_date_test.dart b/tests/standalone/io/http_date_test.dart
index 1c7df410137eae4355b4c8318d71108a2b35ba58..81ed109936f395245b07b9f86c807303e83df8f7 100644
--- a/tests/standalone/io/http_date_test.dart
+++ b/tests/standalone/io/http_date_test.dart
@@ -4,15 +4,15 @@
 
 #import("dart:math");
 
-#source("../../../runtime/bin/input_stream.dart");
-#source("../../../runtime/bin/output_stream.dart");
-#source("../../../runtime/bin/chunked_stream.dart");
-#source("../../../runtime/bin/string_stream.dart");
-#source("../../../runtime/bin/stream_util.dart");
-#source("../../../runtime/bin/http.dart");
-#source("../../../runtime/bin/http_impl.dart");
-#source("../../../runtime/bin/http_parser.dart");
-#source("../../../runtime/bin/http_utils.dart");
+#source("../../../lib/io/input_stream.dart");
+#source("../../../lib/io/output_stream.dart");
+#source("../../../lib/io/chunked_stream.dart");
+#source("../../../lib/io/string_stream.dart");
+#source("../../../lib/io/stream_util.dart");
+#source("../../../lib/io/http.dart");
+#source("../../../lib/io/http_impl.dart");
+#source("../../../lib/io/http_parser.dart");
+#source("../../../lib/io/http_utils.dart");
 
 void testParseHttpDate() {
   Date date;