* Make _sanityCheck internal
* Make _debugPrecondition internal
* Make Optional._unsafelyUnwrappedUnchecked internal.
* Make _precondition internal
* Switch Foundation _sanityChecks to assertions
* Update file check tests
* Remove one more _debugPrecondition
* Update Optimization-with-check tests
I want to create some larger/more expensive workloads for this. So move all
StringComparison initialization out of the loop just to be standard.
rdar://40371840