Symfony version(s) affected: 3.x, 4.x

Description
Due to update in php-intl library this loop is infinite.

How to reproduce
Update php-intl to the latest version and try to get country names for en locale for example.

Possible Solution
For BC it would be great to loop until locale is empty so check could be !empty($currentlocale)

Additional context
Ive been struggling with this all morning, later I had to code on my laptop and this error was not present, Ive updated php-intl and error became present as on my work PC.