[DependencyInjection] fixes #9815 Syntax error in PHP dumper
bug #9816 [DependencyInjection] fixes #9815 Syntax error in PHP dumper (realityking)

This PR was merged into the 2.5-dev branch.

Discussion
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[DependencyInjection] fixes #9815 Syntax error in PHP dumper

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9815
| License       | MIT
| Doc PR        | -

I also updated the unit tests to test a namespaces class to prevent future issues like this one.

Commits
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e00b0f3 [DependencyInjection] fixes #9815 Syntax error in PHP dumper
added mongodb, memcached, memcache extension to run tests that were previously skipped