Rule source on GitHub

DowngradeReflectionClassGetConstantsFilterRector

Downgrade ReflectionClass->getConstants(ReflectionClassConstant::IS_*)

 $reflectionClass = new ReflectionClass('SomeClass');
-$constants = $reflectionClass->getConstants(ReflectionClassConstant::IS_PUBLIC));
+$reflectionClassConstants = $reflectionClass->getReflectionConstants();
+$result = [];
+array_walk($reflectionClassConstants, function ($value) use (&$result) {
+    if ($value->isPublic()) {
+       $result[$value->getName()] = $value->getValue();
+    }
+});
+$constants = $result;

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\DowngradePhp80\Rector\MethodCall\DowngradeReflectionClassGetConstantsFilterRector;

return RectorConfig::configure()
    ->withRules([
        DowngradeReflectionClassGetConstantsFilterRector::class,
    ]);