swift

e2708f79 - AST: introduce the opposite options for ABIBreakingToAdd and others

AST: introduce the opposite options for ABIBreakingToAdd and others Adding ABIBreakingToAdd and other options for decl attribute kind isn't sufficient because future attributes may forget to add the ABI/API impact bits. This patch introduces the opposite options of these breaking bits (ABIStableToAdd, etc) , and adds several static assertions to ensure one of the opposite ABI/API impact flags is explicitly specified.