bug #31856 [VarDumper] fix dumping the cloner itself (nicolas-grekas)
bug #31856 [VarDumper] fix dumping the cloner itself (nicolas-grekas)

This PR was merged into the 4.3 branch.

Discussion
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[VarDumper] fix dumping the cloner itself

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Having PHP references inside the cloner badly breaks it when it finds itself in the dumped graph.
Let's remove this optimization, and skip dumping cloners by default as a bonus.

Commits
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3cd56cb018 [VarDumper] fix dumping the cloner itself

symfony/var-dumper,symfony/var-dumper