With a recent change of mine (#9989 <https://github.com/apple/swift/pull/9989>) subscripts are no longer represented internally by the identifier "subscript" but by a DeclBaseName with a special flag. In name mangling, however, the string "subscript" still surfaces (e.g. _T04test3FooC9subscriptyycfg). I think that we should use a special flag here instead, similar to "fC" for constructors or "fD" for destructors.
I don't know much about the mangling and which considerations need to be taken here though, so: Would this be a change that is worth doing, even though it gives no immediate benefit? If yes, could someone assist me with the design work of choosing the right mangling scheme or take over the issue? Or should I just file a JIRA for it, assign it the label "AffectsABI" and wait for someone to pick it up as the ABI gets stabilised?