Fix handle leak in EvalExpressionExhaustCIDs test.

runtime/vm/compiler_test.cc

 // 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.
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/object.h"
 #include "vm/symbols.h"
@@ skipping 105 matching lines @@
 
 
 TEST_CASE(EvalExpressionExhaustCIDs) {
   Library& lib = Library::Handle(Library::CoreLibrary());
 
   const String& expression = String::Handle(String::New("3 + 4"));
   Object& val = Object::Handle();
 
   const intptr_t classTableSize = 1 << RawObject::kClassIdTagSize;
   for (intptr_t i = 0; i < classTableSize; i++) {
+    StackZone zone(Isolate::Current());
     val = lib.Evaluate(expression, Array::empty_array(), Array::empty_array());
   }
 
   EXPECT(!val.IsNull());
   EXPECT(!val.IsError());
   EXPECT(val.IsInteger());
   EXPECT_EQ(7, Integer::Cast(val).AsInt64Value());
 }
 
 }  // namespace dart