Simplify some code with null coalesce operator

Author: javiereguiluz

EventListener/DebugHandlersListener.php

@@ -60,7 +60,7 @@ public function __construct(callable $exceptionHandler = null, LoggerInterface $
 
         $this->exceptionHandler = $exceptionHandler;
         $this->logger = $logger;
-        $this->levels = null === $levels ? \E_ALL : $levels;
+        $this->levels = $levels ?? \E_ALL;
         $this->throwAt = \is_int($throwAt) ? $throwAt : (null === $throwAt ? null : ($throwAt ? \E_ALL : null));
         $this->scream = $scream;
         $this->fileLinkFormat = $fileLinkFormat;

Profiler/Profile.php

@@ -156,11 +156,7 @@ public function setUrl($url)
      */
     public function getTime()
     {
-        if (null === $this->time) {
-            return 0;
-        }
-
-        return $this->time;
+        return $this->time ?? 0;
     }
 
     /**

Tests/KernelTest.php

@@ -709,7 +709,7 @@ protected function getBundle($dir = null, $parent = null, $className = null, $bu
         $bundle
             ->expects($this->any())
             ->method('getName')
-            ->willReturn(null === $bundleName ? \get_class($bundle) : $bundleName)
+            ->willReturn($bundleName ?? \get_class($bundle))
         ;
 
         $bundle