Apply hints suggested by the multi-arch hinter

Apply hints suggested by the multi-arch hinter.

These changes were suggested on https://wiki.debian.org/MultiArch/Hints.

Note that in some cases, these multi-arch hints may trigger lintian warnings until the dependencies of the package support multi-arch. This is expected, see https://janitor.debian.net/multiarch-fixes#why-does-lintian-warn for details.

This merge proposal was created automatically by the Janitor bot. For more information, including instructions on how to disable these merge proposals, see https://janitor.debian.net/multiarch-fixes.

You can follow up to this merge proposal as you normally would.

The bot will automatically update the merge proposal to resolve merge conflicts or close the merge proposal when all changes are applied through other means (e.g. cherry-picks). Updates may take several hours to propagate.

Build and test logs for this branch can be found at https://janitor.debian.net/multiarch-fixes/pkg/libcxx-serial/63e96820-ec65-49e0-b3f7-88e1a80fb7f7.

Debdiff

These changes affect the binary packages:

File lists identical (after any substitutions)

Control files of package libcxx-serial-dev: lines which differ (wdiff format)

• Multi-Arch: same

No differences were encountered between the control files of package **libcxx-serial1**

No differences were encountered between the control files of package **libcxx-serial1-dbgsym**

You can also view the diffoscope diff (unfiltered).