swift

244a5f7a - Sema: Fix crash with recursive subscript validation via associated type inference

Sema: Fix crash with recursive subscript validation via associated type inference Looks like subscript validation wasn't checking or setting ValueDecl::isBeingValidated(). This caused a stack overflow with associated type inference. The way to trigger this during normal use is to invoke the fixit for adding missing protocol requirements -- they're written in terms of the protocol's associated type, which the user might not have defined yet. Fixes <rdar://problem/26680599>.