Merge branch '3.2' into 3.3

* 3.2:
  Fix optional cache warmers are always instantiated whereas they should be lazy-loaded
  add some \ on PHP_VERSION_ID for 2.8
  [PropertyInfo][DoctrineBridge] The bigint Doctrine's type must be converted to string

Author: nicolas-grekas

Tests/Resource/ReflectionClassResourceTest.php

@@ -124,10 +124,10 @@ public function provideHashedSignature()
         yield array(0, 8, '/** priv docblock */');
         yield array(0, 9, 'private $priv = 123;');
         yield array(1, 10, '/** pub docblock */');
-        if (PHP_VERSION_ID >= 50600) {
+        if (\PHP_VERSION_ID >= 50600) {
             yield array(1, 11, 'public function pub(...$arg) {}');
         }
-        if (PHP_VERSION_ID >= 70000) {
+        if (\PHP_VERSION_ID >= 70000) {
             yield array(1, 11, 'public function pub($arg = null): Foo {}');
         }
         yield array(0, 11, "public function pub(\$arg = null) {\nreturn 123;\n}");