Is your feature request related to a problem? Please describe.
OS_SelectMultipe, OS_SelectSingle, OS_SelectFdZero, OS_SelectFdAdd, OS_SelectFdClear, OS_SelectFdIsSet all missing functional tests

Describe the solution you'd like
Add tests

Describe alternatives you've considered
None

Additional context
Certification issue.

Requester Info
Jacob Hageman - NASA/GSFC