Add missing header required by gnu 15

[prgillies]

Description

This fixes a compilation failure when using gnu 15.2.0 which fails due to the missing include file. Once this is merged could you create a new tag with this fix as we would like to start testing IFS with gnu 15, thanks!

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

[prgillies]

@marcosbento I can't see the reviewers so pinging you here in case you're not aware of this 👍

[marcosbento]

Sorry, I missed your ping but the issue is now fixed. There was also an annoying warning that should now be suppressed.

[prgillies]

Thanks for fixing this @marcosbento, can we have a tag with this fix please.