Remove NullPointerException.

pkg/fixnum/test/int_64_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library int64test;
 import '../lib/fixnum.dart';
 
 void main() {
   testAdditive();
   testBitOps();
@@ skipping 127 matching lines @@
   Expect.isTrue(!(largePos > largePos));
 
   Expect.isTrue(!(largePosPlusOne < largePos));
   Expect.isTrue(!(largePosPlusOne <= largePos));
   Expect.isTrue(!(largePosPlusOne == largePos));
   Expect.isTrue(largePosPlusOne >= largePos);
   Expect.isTrue(largePosPlusOne > largePos);
 
   try {
     new int64.fromInt(17) < null;
-    Expect.fail("x < null should throw NullPointerException");
-  } on NullPointerException catch (e) {
+    Expect.fail("x < null should throw ArgumentError");
+  } on ArgumentError catch (e) {
   }
 
   try {
     new int64.fromInt(17) <= null;
-    Expect.fail("x <= null should throw NullPointerException");
-  } on NullPointerException catch (e) {
+    Expect.fail("x <= null should throw ArgumentError");
+  } on ArgumentError catch (e) {
   }
 
   try {
     new int64.fromInt(17) > null;
-    Expect.fail("x > null should throw NullPointerException");
-  } on NullPointerException catch (e) {
+    Expect.fail("x > null should throw ArgumentError");
+  } on ArgumentError catch (e) {
   }
 
   try {
     new int64.fromInt(17) < null;
-    Expect.fail("x >= null should throw NullPointerException");
-  } on NullPointerException catch (e) {
+    Expect.fail("x >= null should throw ArgumentError");
+  } on ArgumentError catch (e) {
   }
 
   Expect.isFalse(new int64.fromInt(17) == null);
 }
 
 void testConversions() {
   Expect.equals(0, new int64.fromInt(0).toInt());
   Expect.equals(100, new int64.fromInt(100).toInt());
   Expect.equals(-100, new int64.fromInt(-100).toInt());
   Expect.equals(2147483647, new int64.fromInt(2147483647).toInt());
@@ skipping 419 matching lines @@
   Expect.equals("777777777777777777777", int64.MAX_VALUE.toRadixString(8));
   Expect.equals("67404283172107811827", int64.MAX_VALUE.toRadixString(9));
   Expect.equals("9223372036854775807", int64.MAX_VALUE.toRadixString(10));
   Expect.equals("1728002635214590697", int64.MAX_VALUE.toRadixString(11));
   Expect.equals("41A792678515120367", int64.MAX_VALUE.toRadixString(12));
   Expect.equals("10B269549075433C37", int64.MAX_VALUE.toRadixString(13));
   Expect.equals("4340724C6C71DC7A7", int64.MAX_VALUE.toRadixString(14));
   Expect.equals("160E2AD3246366807", int64.MAX_VALUE.toRadixString(15));
   Expect.equals("7FFFFFFFFFFFFFFF", int64.MAX_VALUE.toRadixString(16));
 }