Up to four different proposals were made, and it looks like we can’t agree on one (or some hybrid). Let’s give this another try by having most (all?) interested people in the same room.
The most recent proposal (agreed upon by at least two parties) was something as simple as FUNC(), DATA(), and END(), with the former two annotating the beginning of a “range” of interest, supplying the ELF type annotation, while END() would mark the “range”s ending and at the same time supply the ELF size annotation. Flavors of these would exist to annotate non-global functions/data.
Of course ideally whichever chosen approach could be used by other architectures as well, and then be generic rather than arch-specific in the sources.