Make OutOfMemory test work on 32 bit machines.

runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart

Index: runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart
diff --git a/runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart b/runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart
index 24bb08319dd72a024127d04f15970d5bd482e443..2cdf4a0a81dc93542970787f0e80f66c92f42254 100644
--- a/runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart
+++ b/runtime/observatory/tests/service/get_isolate_after_out_of_memory_error_test.dart
@@ -10,7 +10,18 @@ import 'service_test_common.dart';
 import 'dart:math';
 
 void goOutOfMemory() {
-  new List(pow(2, 53));
+  // Trying to allocate an array larger than Array::kMaxElements
+  // results in a RangeError instead of an OutOfMemoryError.
+  // To always obtain an OutOfMemoryError we create more than one List.
+  List<List> out = <List>[];
+  // This generates an exception on 32 bit machines.
+  for (var i = 0; i < 8; i++) {
+    out.add(new List(pow(2, 28) - 1));
+  }
+  // This generates an exception on 64 bit machines.
+  for (var i = 0; i < 64; i++) {
+    out.add(new List(pow(2, 58) - 1));
+  }
 }
 
 var tests = [