Remove Expect from core library.

tests/standalone/io/process_check_arguments_script.dart

Index: tests/standalone/io/process_check_arguments_script.dart
diff --git a/tests/standalone/io/process_check_arguments_script.dart b/tests/standalone/io/process_check_arguments_script.dart
index de5df11246e4c892a71c69273b4de31890eb591b..4e933b9f9fae9f534ede17902e3c462304e497a9 100644
--- a/tests/standalone/io/process_check_arguments_script.dart
+++ b/tests/standalone/io/process_check_arguments_script.dart
@@ -7,6 +7,20 @@
 import "dart:math";
 import "dart:io";
 
+class Expect {
+  static void isTrue(x) {
+    if (!x) {
+      throw new Error("Not true");
+    }
+  }
+
+  static void equals(x, y) {
+    if (x != y) {
+      throw new Error("Not equal");
+    }
+  }
+}
+
 main() {
   var options = new Options();
   Expect.isTrue(options.script.endsWith('process_check_arguments_script.dart'));