Removing check to RLIMIT_NOFILE in select call.
Adding unit test to select suite to document behavior.
Moving setrlimit class from mlock to a util file for reuse.
Fixing flaky test based on comments from Jamie.
PiperOrigin-RevId: 228726131
Change-Id: Ie9dbe970bbf835ba2cca6e17eec7c2ee6fadf459
Zach Koopmans