cwrappers vs (old)wrappers: status and path forward?

[Greg Troxel <gdt%lexort.com@localhost>]

I don't have the energy to work on this at all, but recent discussion
about optional rust reminded me that we are still perhaps partway
through a wrappers transition.

We have wrappers from before, and cwrappers.  cwrappers has been default
for a really long time.  I wonder then:

  - Do people believe that they are totally equivalent functionally?
    Or do we have "(old)wrappers is buggy in case X; fixed in
    cwrappers"?

  - Do people believe that it makes sense to still have the old
    wrappers?  Are they for bootstrapping?  In case of bugs?   Not
    needed?  Something else?

  - What do people think would happen if someone set USE_CWRAPPERS=no,
    ran into a problem, and reported it?  Anything other than being told
    they should use cwrappers?