[DI] Fix possible incorrect php-code when dumped strings contains newlines#24532

Strate wants to merge 4 commits intosymfony:2.7symfony/symfony:2.7from

Strate:issue_24470_as_files_dumper_fix_2_7Strate/symfony:issue_24470_as_files_dumper_fix_2_7Copy head branch name to clipboard