swift

87b31276 - [swift-vfe] Disable for @objc classes

[swift-vfe] Disable for @objc classes Swift methods can be called from Objective-C without a vtable load, and more importantly without emitting an `llvm.type.checked.load` instruction. These are effectively virtual callsites that are not visible to the VFE logic in GlobalDCE. To to safely enable swift-vfe we must prevent vtables whose functions are callable from Objective-C from being eliminated. To do this we ensure such vtables have public vcall_visibility, which indirectly prevents GlobalDCE from stripping them.