Tag build swift-DEVELOPMENT-SNAPSHOT-2017-01-24-a
Merge remote-tracking branch 'origin/swift-4.0-branch' into stable

* origin/swift-4.0-branch:
  Merging r292847: ------------------------------------------------------------------------ r292847 | rsmith | 2017-01-23 15:14:23 -0800 (Mon, 23 Jan 2017) | 2 lines
  Merging r292800: ------------------------------------------------------------------------ r292800 | dergachev | 2017-01-23 08:57:11 -0800 (Mon, 23 Jan 2017) | 13 lines
  Merging r292497: ------------------------------------------------------------------------ r292497 | arphaman | 2017-01-19 09:17:57 -0800 (Thu, 19 Jan 2017) | 6 lines
  Merging r292555, r292558 and r292559: ------------------------------------------------------------------------ r292555 | rsmith | 2017-01-19 16:45:35 -0800 (Thu, 19 Jan 2017) | 6 lines