* 2.8:
Fix Clidumper tests
Enable the fixer enforcing fully-qualified calls for compiler-optimized functions
Apply fixers
Disable the native_constant_invocation fixer until it can be scoped
Update the list of excluded files for the CS fixer
This removes the unused use statements which were not catched by
PHP-CS-Fixer because of string occurences. It also fixes some invalid
phpdoc (scalar is not recognized as a valid type for instance).