[PATCH] D34249: [libc++] Don't use UTIME_OMIT to detect utimensat on Apple

[Nico Weber via Phabricator via cfe-commits]

thakis added a comment.

I went ahead and landed this with the comments requested by Duncan in r324385. (http://llvm.org/viewvc/llvm-project?view=revision&revision=324385)

I'm also quoting Duncan's email reply to my comment, since that's not showing up on phab:
"""
Using runtime availability checking doesn't make sense for a system Libc++, as you point out.  If we add runtime checks they ought to be non-default, and hidden behind configuration flags.

Also, do I remember correctly that __builtin_available requires linking against Foundation (and thus the Obj-C runtime) for NSProcessInfo, or has that dependency been removed/avoided?  It would be surprising for the C++ standard library to pull in the Objective-C runtime.  A reasonable configuration option, but not a reasonable default behaviour IMO.
"""


https://reviews.llvm.org/D34249