[Translation][Debug] Add installation and minimal example to README

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2004-2019 Fabien Potencier
+Copyright (c) 2004-2020 Fabien Potencier
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -3,10 +3,22 @@ Debug Component
 
 The Debug component provides tools to ease debugging PHP code.
 
+Getting Started
+---------------
+
+```
+$ composer install symfony/debug
+```
+
+```php
+use Symfony\Component\Debug\Debug;
+
+Debug::enable();
+```
+
 Resources
 ---------
 
-  * [Documentation](https://symfony.com/doc/current/components/debug/index.html)
   * [Contributing](https://symfony.com/doc/current/contributing/index.html)
   * [Report issues](https://github.com/symfony/symfony/issues) and
     [send Pull Requests](https://github.com/symfony/symfony/pulls)

Tests/Exception/FlattenExceptionTest.php

@@ -199,6 +199,10 @@ class FlattenExceptionTest extends TestCase
 
     public function testArguments()
     {
+        if (\PHP_VERSION_ID >= 70400) {
+            $this->markTestSkipped('PHP 7.4 removes arguments from exception traces.');
+        }
+
         $dh = opendir(__DIR__);
         $fh = tmpfile();
 
@@ -261,6 +265,10 @@ class FlattenExceptionTest extends TestCase
 
     public function testRecursionInArguments()
     {
+        if (\PHP_VERSION_ID >= 70400) {
+            $this->markTestSkipped('PHP 7.4 removes arguments from exception traces.');
+        }
+
         $a = null;
         $a = ['foo', [2, &$a]];
         $exception = $this->createException($a);
@@ -272,6 +280,10 @@ class FlattenExceptionTest extends TestCase
 
     public function testTooBigArray()
     {
+        if (\PHP_VERSION_ID >= 70400) {
+            $this->markTestSkipped('PHP 7.4 removes arguments from exception traces.');
+        }
+
         $a = [];
         for ($i = 0; $i < 20; ++$i) {
             for ($j = 0; $j < 50; ++$j) {

Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php

@@ -29,6 +29,10 @@ class ClassNotFoundFatalErrorHandlerTest extends TestCase
             // get class loaders wrapped by DebugClassLoader
             if ($function[0] instanceof DebugClassLoader) {
                 $function = $function[0]->getClassLoader();
+
+                if (!\is_array($function)) {
+                    continue;
+                }
             }
 
             if ($function[0] instanceof ComposerClassLoader) {