Mark resynthesize_kernel_test as slow.

pkg/pkg.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.
 
 # Don't run any test-like files that show up in packages directories. It
 # shouldn't be necessary to run "pub install" in these packages, but if you do
 # it shouldn't break the tests.
 */packages/*/*: Skip
 */*/packages/*/*: Skip
 */*/*/packages/*/*: Skip
 */*/*/*/packages/*/*: Skip
 */*/*/*/*/packages/*/*: Skip
 
 analysis_server/tool/spec/check_all_test: Skip  # Issue 29133
 analyzer_plugin/tool/spec/check_all_test: Skip  # Issue 29133
 analyzer/tool/summary/check_test: Skip  # Issue 29133
 
 analyzer/test/generated/compile_time_error_code_driver_test: Slow, Pass
 analyzer/test/generated/non_error_resolver_driver_test: Slow, Pass
 analyzer/test/generated/static_warning_code_driver_test: Slow, Pass
 analyzer/test/generated/compile_time_error_code_test: Slow, Pass
+analyzer/test/src/summary/resynthesize_kernel_test: Slow, Pass
 
 # Analyzer2dart is not maintained anymore.
 analyzer2dart/test/*: Skip
 
 dart_messages/test/dart_messages_test: Skip  # Requires a package root.
 
 # Skip dev_compiler codegen tests
 dev_compiler/test/codegen/*: Skip
 dev_compiler/gen/*: SkipByDesign
 
@@ skipping 184 matching lines @@
 kernel/test/closures_test: Fail
 
 [ $runtime == vm ]
 analyzer_cli/test/driver_test: Pass, Slow, Timeout
 
 [ $runtime == vm && $system == windows ]
 analyzer/test/src/task/strong/checker_test: Pass, Slow
 
 [ $browser ]
 testing/test/analyze_test: SkipByDesign