#369413 by bjaspan: Reset Field API caches in DrupalWebTestCase->tearDown().

modules/simpletest/drupal_web_test_case.php

@@ -928,6 +928,9 @@ protected function tearDown() {
       module_list(TRUE);
       module_implements(MODULE_IMPLEMENTS_CLEAR_CACHE);
 
+      // Reset the Field API.
+      field_cache_clear();
+
       // Rebuild caches.
       $this->refreshVariables();