Symfony version(s) affected: 4.4

Description
We have a FileDumper that converts messages.en.yml to messages.en.php files. Since 4.4 this file became message+intl-icu.en.php with the same content.

Upon reading these +incl-icu.php files, the %placeholder% are no longer replaced with the correct value.

Spoke with @yceruto in #35264 (comment) and he suggested this is a different issue.

How to reproduce
See commits on https://github.com/ruudk/symfony-translation-bug-poc/commits/master

Possible Solution
The FileDumper should not just add +intl-icu to files.