Fixing lgtm.yml to include test code+ small fix

[raulgarciamsft]

• Fixing lgtm.yml to include test code
• Fixing header guard for builtins.h

Checklist

🚨Please review the guidelines for contributing to this repository.

• 🤔 CONSIDER adding a unit test if your PR resolves an issue.
• ✅ DO check open PR's to avoid duplicates.
• ✅ DO keep pull requests small so they can be easily reviewed.
• ✅ DO build locally before pushing.
• ✅ DO make sure tests pass.
• ✅ DO make sure any new changes are documented.
• ✅ DO make sure not to introduce any compiler warnings.
• ❌AVOID breaking the continuous integration build.
• ❌AVOID making significant changes to the overall architecture.

Description

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💔Thank you!

[lgtm-com]

This pull request fixes 1 alert when merging 528fa77 into 7bf64a3 - view on LGTM.com

fixed alerts:

• 1 for Missing header guard