debuginfo: Describe item and member visibility in debugging information

[michaelwoerister]

This can be done using the flags parameter of various llvm::DIBuilder methods (e.g. createMemberType).

[flaper87]

Triage. This doesn't appear to have been implemented yet.

[steveklabnik]

Triage: no idea. @michaelwoerister what's the status of this today?

[michaelwoerister]

Still not implement, AFAIK.

[steveklabnik]

Triage: I am not aware of any changes here.

[Alexendoo]

Triage: Hi, are you still working on this issue @ernestask?

[wesleywiser]

Visited during wg-debugging triage. Representing Rust semantics in debuginfo is useful but this kind of thing doesn't tend to affect the experience of debugging Rust code (this sort of thing is often used by tools other than the debugger which build on top of DWARF/CodeView). Marking as P-low.