I had the same problem with builder.php after migrating to 4.5 but i didn´t want to install another or old php version. I solved this when i changed the line in vendor/laravel/framework/src/Illuminate/Database/Query/Builder.php
from
$this->wheres[] = compact('type', 'operator', 'query', 'boolean');
to
"$this->wheres[] = compact('type', 'query', 'boolean');
The reminders are send and the problem is gone.