Broken constructor in v1.5

[mhauru]

ADTypes.AutoReverseDiff(false) used to be a valid way to call the constructor before v1.5 and efdc12e, but now only the keyword argument version works. I appreciate that the positional argument constructor was undocumented, but maybe a deprecation warning could still be put in place?

[ChrisRackauckas]

Yeah we can add that as a deprecation path. Totally not intended as a constructor to use before 😅, but no harm in making it a deprecation.