[Bug c++/62306] [4.9/5 Regression?] Change in the comdat used for constructors

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62306

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
You could e.g. implement the dtors as:
_Z...D0...:
  set some hard reg to 0
  tail call some function
_Z...D1...:
  set some hard reg to 1
  tail call some function
_Z...D2...:
  set some hard reg to 2
  tail call some function
and that function would just have a magic extra argument, if the same in
between all levels would not use it at all, otherwise could e.g. have if (extra
== 0) delete ...; at the end, etc.

My memory is fuzzy on it after all the years, but as the comdat names are part
of the ABI, I think the idea was to allow implementations to choose how to
implement it while staying interoperable.

So, if g++ 4.[569]/5 emit it in D5, I think that is how it was meant, and what
should be done.