diff -u b/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
--- b/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -159,6 +159,17 @@
 }
 
 /**
+ * Extends the custom PHP error handling.
+ */
+function _drupal_php_shutdown_error_handler() {
+  require_once __DIR__ . '/errors.inc';
+  _drupal_php_shutdown_error_handler_real();
+}
+
+// Set the Drupal custom error handler. (requires config())
+drupal_register_shutdown_function('_drupal_php_shutdown_error_handler');
+
+/**
  * Provides custom PHP exception handling.
  *
  * Uncaught exceptions are those not enclosed in a try/catch block. They are
@@ -962,17 +973,6 @@
 }
 
 /**
- * Extends the custom PHP error handling.
- */
-function _drupal_php_shutdown_error_handler() {
-  require_once __DIR__ . '/errors.inc';
-  _drupal_php_shutdown_error_handler_real();
-}
-
-// Set the Drupal custom error handler. (requires config())
-drupal_register_shutdown_function('_drupal_php_shutdown_error_handler');
-
-/**
  * Provides custom PHP exception handling.
  *
  * Uncaught exceptions are those not enclosed in a try/catch block. They are
interdiff impossible; taking evasive action
reverted:
--- b/core/includes/errors.inc
+++ a/core/includes/errors.inc
@@ -80,53 +80,6 @@
 }
 
 /**
- * Extends the custom PHP error handling to handle error types that cannot be
- * captured by the standard PHP error handler.
- */
-function _drupal_php_shutdown_error_handler_real() {
-  // As defined at http://php.net/manual/en/function.set-error-handler.php
-  // following error types cannot be handled by the custom defined error handler
-  // callback.
-  $error_types = array(
-    E_ERROR,
-    E_CORE_ERROR,
-    E_CORE_WARNING,
-    E_COMPILE_ERROR,
-    E_COMPILE_WARNING,
-  );
-
-  // Check if an error was thrown and it's one that can only be captured by a
-  // shutdown function.
-  if (!($error = error_get_last()) || !in_array($error['type'], $error_types)) {
-    return;
-  }
-
-  $error_level = $error['type'];
-
-  $types = drupal_error_levels();
-  list($severity_msg, $severity_level) = $types[$error_level];
-
-  if (!function_exists('filter_xss_admin')) {
-    require_once __DIR__ . '/common.inc';
-  }
-
-  // We treat recoverable errors as fatal.
-  _drupal_log_error(array(
-    '%type' => isset($types[$error_level]) ? $severity_msg : 'Unknown error',
-    // The standard PHP error handler considers that the error messages
-    // are HTML. We mimick this behavior here.
-    '!message' => filter_xss_admin($error['message']),
-    // The function info is not provided.
-    '%function' => '',
-    '%file' => $error['file'],
-    '%line' => $error['line'],
-    'severity_level' => $severity_level,
-    // There is not useful backtrace in this case.
-    'backtrace' => array(),
-  ), TRUE);
-}
-
-/**
  * Determines whether an error should be displayed.
  *
  * When in maintenance mode or when error_level is ERROR_REPORTING_DISPLAY_ALL,
unchanged:
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -17,7 +17,7 @@
  * Maps PHP error constants to watchdog severity levels.
  *
  * The error constants are documented at
- * http://php.net/manual/errorfunc.constants.php
+ * http://php.net/manual/errorfunc.constants.php.
  *
  * @ingroup logging_severity_levels
  */
@@ -104,6 +104,53 @@ function _drupal_error_handler_real($error_level, $message, $filename, $line) {
 }
 
 /**
+ * Extends the custom PHP error handling to handle error types that cannot be
+ * captured by the standard PHP error handler.
+ */
+function _drupal_php_shutdown_error_handler_real() {
+  // As defined at http://php.net/manual/en/function.set-error-handler.php
+  // following error types cannot be handled by the custom defined error handler
+  // callback.
+  $error_types = [
+    E_ERROR,
+    E_CORE_ERROR,
+    E_CORE_WARNING,
+    E_COMPILE_ERROR,
+    E_COMPILE_WARNING,
+  ];
+
+  // Check if an error was thrown and it's one that can only be captured by a
+  // shutdown function.
+  if (!($error = error_get_last()) || !in_array($error['type'], $error_types)) {
+    return;
+  }
+
+  $error_level = $error['type'];
+
+  $types = drupal_error_levels();
+  [$severity_msg, $severity_level] = $types[$error_level];
+
+  if (!function_exists('filter_xss_admin')) {
+    require_once __DIR__ . '/common.inc';
+  }
+
+  // We treat recoverable errors as fatal.
+  _drupal_log_error([
+    '%type' => isset($types[$error_level]) ? $severity_msg : 'Unknown error',
+    // The standard PHP error handler considers that the error messages
+    // are HTML. We mimick this behavior here.
+    '!message' => filter_xss_admin($error['message']),
+    // The function info is not provided.
+    '%function' => '',
+    '%file' => $error['file'],
+    '%line' => $error['line'],
+    'severity_level' => $severity_level,
+    // There is not useful backtrace in this case.
+    'backtrace' => [],
+  ], TRUE);
+}
+
+/**
  * Determines whether an error should be displayed.
  *
  * When in maintenance mode or when error_level is ERROR_REPORTING_DISPLAY_ALL,
@@ -236,7 +283,6 @@ function _drupal_log_error($error, $fatal = FALSE) {
 
       if ($error_level != ERROR_REPORTING_DISPLAY_VERBOSE) {
         // Without verbose logging, use a simple message.
-
         // We use \Drupal\Component\Render\FormattableMarkup directly here,
         // rather than use t() since we are in the middle of error handling, and
         // we don't want t() to cause further errors.
@@ -244,7 +290,6 @@ function _drupal_log_error($error, $fatal = FALSE) {
       }
       else {
         // With verbose logging, we will also include a backtrace.
-
         // First trace is the error itself, already contained in the message.
         // While the second trace is the error source and also contained in the
         // message, the message doesn't contain argument values, so we output it