[ClassLoader] Fix undefined index in ClassCollectionLoader
Minor phpcs fixes
minor #12886 Minor phpcs fixes (acrobat)

This PR was merged into the 2.3 branch.

Discussion
----------

Minor phpcs fixes

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

Small phpcs fixes

Commits
-------

9a0d5c3 Minor phpcs fixes
fix phpdoc's alignment
minor #12887 [2.3] CS Fixes: fix phpdoc's alignment (keradus)

This PR was merged into the 2.3 branch.

Discussion
----------

[2.3] CS Fixes: fix phpdoc's alignment

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

Fix phpdoc's alignment

Commits
-------

f588610 fix phpdoc's alignment
bug #12858 [ClassLoader] Fix undefined index in ClassCollectionLoader (szicsu)

This PR was merged into the 2.3 branch.

Discussion
----------

[ClassLoader] Fix undefined index in ClassCollectionLoader

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

Commits
-------

cfdb925 [ClassLoader] Fix undefined index in ClassCollectionLoader
Merge branch '2.3' into 2.5

* 2.3:
  fix phpdoc's alignment
  Minor phpcs fixes
  [ClassLoader] Fix undefined index in ClassCollectionLoader

Conflicts:
	src/Symfony/Component/Serializer/Encoder/XmlEncoder.php