Mark ThreadIterator_AddFindRemove test as flaky.

runtime/tests/vm/vm.status

 # 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.
 
 # These tests are expected to crash on all platforms.
 cc/ArrayNew_Overflow_Crash: Crash
 cc/AllocGeneric_Overflow: Crash, Timeout
 cc/CodeImmutability: Crash
 
 cc/SNPrint_BadArgs: Skip
 
 # Flaky on buildbot. Issue 5133 and 10409.
 cc/Sleep: Pass, Fail
 
+cc/ThreadIterator_AddFindRemove: Pass, Fail # Issue 24700
+
 [ $mode == debug ]
 # This is a benchmark that is not informative in debug mode.
 cc/CorelibIsolateStartup: Skip
 # Negative tests of VerifiedMemory should crash iff in DEBUG mode.
 # TODO(koda): Improve support for negative tests.
 cc/VerifyImplicit_Crash: Crash
 cc/VerifyExplicit_Crash: Crash
 
 # The following section refers to the dart vm tests which live under
 # runtime/tests/vm/dart.
@@ skipping 68 matching lines @@
 dart/snapshot_version_test: SkipByDesign  # Spawns processes
 dart/spawn_infinite_loop_test: Skip  # VM shutdown test
 dart/spawn_shutdown_test: Skip  # VM Shutdown test
 
 [ $runtime == vm && $mode == debug && $builder_tag == asan ]
 cc/Dart2JSCompileAll: Skip  # Timeout.
 
 [ $noopt ]
 dart/redirection_type_shuffling_test: CompileTimeError # Imports dart:mirrors
 dart/byte_array_test: Crash # Incompatible flag --disable_alloc_stubs_after_gc