[PATCH] D27429: [Chrono][Darwin] On Darwin use CLOCK_UPTIME_RAW instead of CLOCK_MONOTONIC

[Howard Hinnant via Phabricator via cfe-commits]

howard.hinnant added a comment.

One more comment:  `steady_clock::now()` is not allowed to throw an exception because it shall satisfy the requirements of `TrivialClock` ([time.clock]/p1).  And [time.clock.req]/p4/b4 says that a `TrivialClock::now()` does not throw exceptions.


https://reviews.llvm.org/D27429