Merge branch '2.8' into 3.4

* 2.8:
  Add note about changed form processing when using PUT requests
  The debug class loader is always loaded by Debug::enable().
  [Intl] Update ICU data to 62.1

Debug.php

@@ -23,10 +23,7 @@ class Debug
     /**
      * Enables the debug tools.
      *
-     * This method registers an error handler and an exception handler.
-     *
-     * If the Symfony ClassLoader component is available, a special
-     * class loader is also registered.
+     * This method registers an error handler, an exception handler and a special class loader.
      *
      * @param int  $errorReportingLevel The level of error reporting you want
      * @param bool $displayErrors       Whether to display errors (for development) or just log them (for production)

Exception/ClassNotFoundException.php

@@ -26,6 +26,9 @@ class ClassNotFoundException extends FatalErrorException
             $previous->getSeverity(),
             $previous->getFile(),
             $previous->getLine(),
+            null,
+            true,
+            null,
             $previous->getPrevious()
         );
         $this->setTrace($previous->getTrace());

Exception/FatalErrorException.php

@@ -18,9 +18,9 @@ namespace Symfony\Component\Debug\Exception;
  */
 class FatalErrorException extends \ErrorException
 {
-    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null)
+    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null, $previous = null)
     {
-        parent::__construct($message, $code, $severity, $filename, $lineno);
+        parent::__construct($message, $code, $severity, $filename, $lineno, $previous);
 
         if (null !== $trace) {
             if (!$traceArgs) {

Exception/FlattenException.php

@@ -157,7 +157,7 @@ class FlattenException
         return $this->previous;
     }
 
-    public function setPrevious(FlattenException $previous)
+    public function setPrevious(self $previous)
     {
         $this->previous = $previous;
     }

Exception/UndefinedFunctionException.php

@@ -26,6 +26,9 @@ class UndefinedFunctionException extends FatalErrorException
             $previous->getSeverity(),
             $previous->getFile(),
             $previous->getLine(),
+            null,
+            true,
+            null,
             $previous->getPrevious()
         );
         $this->setTrace($previous->getTrace());

Exception/UndefinedMethodException.php

@@ -26,6 +26,9 @@ class UndefinedMethodException extends FatalErrorException
             $previous->getSeverity(),
             $previous->getFile(),
             $previous->getLine(),
+            null,
+            true,
+            null,
             $previous->getPrevious()
         );
         $this->setTrace($previous->getTrace());