Merge branch '3.4' into 4.4

* 3.4:
  account for is_numeric() behavior changes in PHP 8
  fix expected exception messages on PHP 8

Author: fabpot

src/Symfony/Component/Cache/Tests/Adapter/MemcachedAdapterTest.php

@@ -76,7 +76,7 @@ public function testBadOptions($name, $value)
             $this->expectExceptionMessage('constant(): Couldn\'t find constant Memcached::');
         } else {
             $this->expectException('Error');
-            $this->expectExceptionMessage('Undefined class constant \'Memcached::');
+            $this->expectExceptionMessage('Undefined constant Memcached::');
         }
 
         MemcachedAdapter::createConnection([], [$name => $value]);

src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTest.php

@@ -86,7 +86,7 @@ public function testBadOptions(string $name, $value)
             $this->expectExceptionMessage('constant(): Couldn\'t find constant Memcached::');
         } else {
             $this->expectException('Error');
-            $this->expectExceptionMessage('Undefined class constant \'Memcached::');
+            $this->expectExceptionMessage('Undefined constant Memcached::');
         }
 
         MemcachedCache::createConnection([], [$name => $value]);

src/Symfony/Component/Yaml/Inline.php

@@ -161,7 +161,7 @@ public static function dump($value, int $flags = 0): string
                 return 'false';
             case ctype_digit($value):
                 return \is_string($value) ? "'$value'" : (int) $value;
-            case is_numeric($value):
+            case is_numeric($value) && false === strpos($value, "\n"):
                 $locale = setlocale(LC_NUMERIC, 0);
                 if (false !== $locale) {
                     setlocale(LC_NUMERIC, 'C');