[DRAFT] HAX: Try the conformant preprocessor

[DHowett]

Summary of the Pull Request

References

PR Checklist

• Closes #xxx
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Documentation updated. If checked, please file a pull request on our docs repo and link it here: #xxx
• Schema updated.
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[AnuthaDev]

[DHowett]

Windows SDK isn't correct-preprocessor-complaint 😢