feature #37373 [DI] deprecate Definition/Alias::setPrivate() (nicolas-grekas)
feature #37373 [DI] deprecate Definition/Alias::setPrivate() (nicolas-grekas)

This PR was merged into the 5.2-dev branch.

Discussion
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[DI] deprecate Definition/Alias::setPrivate()

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| Deprecations? | yes
| Tickets       | -
| License       | MIT
| Doc PR        | -

Right now, there is a very subtle difference between `setPublic()` and `setPrivate()` that dates back to the FC/BC layer we created to turn services private by default.

We kept this difference to help third party bundles provide support for a wide range of versions of Symfony, but since 5.2 will be released at the same time as 3.4 will enter EOM, we should remove this behavior and deprecate `setPrivate()` to signal the change.

This is what this PR does.

Commits
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1bea690f4d [DI] deprecate Definition/Alias::setPrivate()

symfony/framework-bundle