Description:
------------
As of PHP 7.4.0, running the cyclic garbage collector on variant
objects segfaults.

Test script:
---------------
<?php
$keep = new variant(null);
var_dump(gc_collect_cycles());
?>

Expected result:
----------------
int(0)

Actual result:
--------------
php7_debug.dll!gc_mark_grey(_zend_refcounted * ref, _gc_stack * stack) Line 837 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_gc.c:837)
php7_debug.dll!gc_mark_roots(_gc_stack * stack) Line 977 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_gc.c:977)
php7_debug.dll!zend_gc_collect_cycles() Line 1452 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_gc.c:1452)
php7_debug.dll!zif_gc_collect_cycles(_zend_execute_data * execute_data, _zval_struct * return_value) Line 375 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_builtin_functions.c:375)
php7_debug.dll!ZEND_DO_ICALL_SPEC_RETVAL_USED_HANDLER(_zend_execute_data * execute_data) Line 1314 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_vm_execute.h:1314)
php7_debug.dll!execute_ex(_zend_execute_data * ex) Line 53611 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_vm_execute.h:53611)
php7_debug.dll!zend_execute(_zend_op_array * op_array, _zval_struct * return_value) Line 57913 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend_vm_execute.h:57913)
php7_debug.dll!zend_execute_scripts(int type, _zval_struct * retval, int file_count, ...) Line 1665 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\Zend\zend.c:1665)
php7_debug.dll!php_execute_script(_zend_file_handle * primary_file) Line 2617 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\main\main.c:2617)
php.exe!do_cli(int argc, char * * argv) Line 961 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\sapi\cli\php_cli.c:961)
php.exe!main(int argc, char * * argv) Line 1356 (c:\php-sdk\phpdev\vc15\x86\php-src-7.4\sapi\cli\php_cli.c:1356)