Don't ignore internal classes during preloading

When preloading, it's fine to make use of internal class information,
as we do not support Windows. It is also necessary to allow proper
variance checks against internal classes.

Author: nikic

ext/opcache/ZendAccelerator.c

@@ -4450,7 +4450,6 @@ static int accel_preload(const char *config, zend_bool in_child)
 	}
 	CG(compiler_options) |= ZEND_COMPILE_PRELOAD;
 	CG(compiler_options) |= ZEND_COMPILE_HANDLE_OP_ARRAY;
-	CG(compiler_options) |= ZEND_COMPILE_IGNORE_INTERNAL_CLASSES;
 	CG(compiler_options) |= ZEND_COMPILE_DELAYED_BINDING;
 	CG(compiler_options) |= ZEND_COMPILE_NO_CONSTANT_SUBSTITUTION;
 	CG(compiler_options) |= ZEND_COMPILE_IGNORE_OTHER_FILES;

ext/opcache/tests/preload_variance.inc

@@ -13,10 +13,12 @@ class B extends Z {
 class C extends Z {
     public function method($a): self {}
     public function method2($a): C {}
+    public function method3($a): object {}
 }
 class D extends C {
     public function method($a): self {}
     public function method2($a): D {}
+    public function method3($a): stdClass {}
 }
 
 // Works.