Fix interrupt handling to clear thread interrupt status.

Problem manifested as a lock immediately throwing an exception
after waking from sleep, because the interrupt status for the
thread woke it, but was never cleared.
Fix Mutex#sleep order of operations to get 100% on specs.
Numerous fixes to get CI specs 100% again.

* OpenFile needs to register as finalizable to flush on exit
* Kernel#p needed some port cleanup
* String#gsub's logic needed port cleanup
* Removed passing tags for String#inspect and String#scrub.