Tag build swift-DEVELOPMENT-SNAPSHOT-2016-10-31-a
Merge remote-tracking branch 'origin/swift-3.1-branch' into stable

* origin/swift-3.1-branch:
  [Profile] Update testcase for r283948 (NFC)
  [Coverage] Support for C++17 if initializers
  [Coverage] Support for C++17 switch initializers
  [ubsan] Disable bounds-check for flexible array ivars