Tag build swift-DEVELOPMENT-SNAPSHOT-2017-01-05-a
Merge remote-tracking branch 'origin/swift-3.1-branch' into stable

* origin/swift-3.1-branch:
  Handle StaticAssertDecl in DeclContextPrinter
  Handle VarTemplateDecl in DeclContextPrinter
  Handle AccessSpecDecl in DeclContextPrinter
  Handle ClassTemplateSpecializationDecl in DeclContextPrinter
  Handle EmptyDecl in DeclContextPrinter
  Handle UsingDecl and UsingShadowDecl in DeclContextPrinter
  Handle FriendDecl in DeclContextPrinter
  [CodeCompletion] Autocomplete NS_DESIGNATED_INITIALIZER in initializers with arguments