Merge branch '2.8' into 3.4

* 2.8:
  Enable native_constant_invocation CS fixer

Author: nicolas-grekas

DeprecationErrorHandler.php

@@ -80,7 +80,7 @@ public static function register($mode = 0)
                 return true;
             }
             foreach ($vendors as $vendor) {
-                if (0 === strpos($realPath, $vendor) && false !== strpbrk(substr($realPath, \strlen($vendor), 1), '/'.DIRECTORY_SEPARATOR)) {
+                if (0 === strpos($realPath, $vendor) && false !== strpbrk(substr($realPath, \strlen($vendor), 1), '/'.\DIRECTORY_SEPARATOR)) {
                     return true;
                 }
             }
@@ -159,7 +159,7 @@ public static function register($mode = 0)
                     echo "\n".ucfirst($group).' deprecation triggered by '.$class.'::'.$method.':';
                     echo "\n".$msg;
                     echo "\nStack trace:";
-                    echo "\n".str_replace(' '.getcwd().DIRECTORY_SEPARATOR, ' ', $e->getTraceAsString());
+                    echo "\n".str_replace(' '.getcwd().\DIRECTORY_SEPARATOR, ' ', $e->getTraceAsString());
                     echo "\n";
 
                     exit(1);
@@ -315,7 +315,7 @@ private static function hasColorSupport()
             return true;
         }
 
-        if (DIRECTORY_SEPARATOR === '\\') {
+        if (\DIRECTORY_SEPARATOR === '\\') {
             return (\function_exists('sapi_windows_vt100_support')
                 && sapi_windows_vt100_support(STDOUT))
                 || false !== getenv('ANSICON')