Warm-up to avoid autoloads interfering with class serial

Author: matthewd

activesupport/test/executor_test.rb

@@ -232,6 +232,9 @@ def test_class_serial_is_unaffected
 
     executor.register_hook(hook)
 
+    # Warm-up to trigger any pending autoloads
+    executor.wrap { }
+
     before = RubyVM.stat(:class_serial)
     executor.wrap { }
     executor.wrap { }