Tag build swift-DEVELOPMENT-SNAPSHOT-2017-02-15-a
Merge remote-tracking branch 'origin/swift-4.0-branch' into stable

* origin/swift-4.0-branch:
  Merging r294806: ------------------------------------------------------------------------ r294806 | dim | 2017-02-11 00:48:40 +0100 (Sat, 11 Feb 2017) | 15 lines
  Merging r294886: ------------------------------------------------------------------------ r294886 | weimingz | 2017-02-11 21:10:25 -0800 (Sat, 11 Feb 2017) | 9 lines