Provide debug_backtrace with proper args

This would fail if we were using strict mode with php 7, because true is
only a valid argument for php < 5.3.6.
This was changed from PHP_VERSION_ID >= 50400 ?
DEBUG_BACKTRACE_IGNORE_ARGS | DEBUG_BACKTRACE_PROVIDE_OBJECT : true in
 #18272, but I do not understand why it was simplified, nor why
DEBUG_BACKTRACE_IGNORE_ARGS was there at that time.

src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php

@@ -72,7 +72,7 @@ class DeprecationErrorHandler
             }
 
             $mode = $getMode();
-            $trace = debug_backtrace(true);
+            $trace = debug_backtrace();
             $group = 'other';
 
             $i = \count($trace);