Hi,
in a project that uses api-platform/core, we use maglnet/ComposerRequireChecker to check our dependencies.
Due to a recent update of vimeo/psalm, PHP-Parser got updated to 4.8 which resulted in the error below when running the ComposerRequireChecker:

Syntax error, unexpected T_NS_SEPARATOR on line 122

I managed to narrow it down to these specific packages and versions:

• api-platform/core:2.5.6
• maglnet/composer-require-checker:2.1.0
• nikic/php-parser:4.7.0

Downgrading to nikic/php-parse:4.6.0 "solves" the problem.
Upgrading to either 4.8 or 4.9 does NOT solve the issue.

I've create a dedicated repo with the above mentioned packages/version, that can be used to reproduce the problem: https://github.com/kochen/nikic-php-parser-4.7.0