I am hitting a "maximum execution time" error when attempting to load `/paste/` on our install. Setting `debug.time-limit` to 15 yields the following:
```
Request aborted by debug time limit after 15 seconds.
STACK TRACE
utf8.php:398 PhabricatorStartup->onDebugTick()
utf8.php:693 phutil_utf8v_codepoints()
utf8.php:734 phutil_utf8_is_combining_character()
PhutilUTF8StringTruncator.php:105 phutil_utf8v_combined()
PhabricatorPasteQuery.php:355 PhutilUTF8StringTruncator->truncateString()
PhabricatorPasteQuery.php:322 PhabricatorPasteQuery->buildSnippet()
PhabricatorPasteQuery.php:101 PhabricatorPasteQuery->loadSnippets()
PhabricatorPolicyAwareQuery.php:259 PhabricatorPasteQuery->didFilterPage()
PhabricatorCursorPagedPolicyAwareQuery.php:169 PhabricatorPolicyAwareQuery->execute()
PhabricatorApplicationSearchEngine.php:998 PhabricatorCursorPagedPolicyAwareQuery->executeWithCursorPager()
PhabricatorApplicationSearchController.php:218 PhabricatorApplicationSearchEngine->executeQuery()
PhabricatorApplicationSearchController.php:78 PhabricatorApplicationSearchController->processSearchRequest()
AphrontController.php:29 PhabricatorApplicationSearchController->processRequest()
AphrontController.php:71 AphrontController->handleRequest()
PhabricatorPasteListController.php:17 AphrontController->delegateToController()
AphrontApplicationConfiguration.php:237 PhabricatorPasteListController->handleRequest()
AphrontApplicationConfiguration.php:149 AphrontApplicationConfiguration->processRequest()
index.php:17 AphrontApplicationConfiguration->runHTTPRequest()
```