solver3: Explicitly declare and define ~Solver

On recent armfhf and s390x builds in the PPA, the compiler seems to have
generated the destructor at the wrong point where the definitions where
not yet complete, and it does seem ill-advised to rely on a
default-constructed destructor in the solver for future ABI sake.

In file included from /usr/include/c++/14/vector:66,
                 from /<<PKGBUILDDIR>>/obj-arm-linux-gnueabihf/include/apt-pkg/cachefilter.h:14:
/usr/include/c++/14/bits/stl_vector.h: In instantiation of ‘constexpr std::_Vector_base<_Tp, _Alloc>::~_Vector_base() [with _Tp = APT::Solver::Work; _Alloc = std::allocator<APT::Solver::Work>]’:
/usr/include/c++/14/bits/stl_vector.h:531:7:   required from here
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:369:49: error: invalid use of incomplete type ‘struct APT::Solver::Work’
  369 |                       _M_impl._M_end_of_storage - _M_impl._M_start);
      |                       ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
In file included from /<<PKGBUILDDIR>>/apt-pkg/edsp.cc:22:
/<<PKGBUILDDIR>>/obj-arm-linux-gnueabihf/include/apt-pkg/solver3.h:87:11: note: forward declaration of ‘struct APT::Solver::Work’
   87 |    struct Work;
      |           ^~~~
/usr/include/c++/14/bits/stl_vector.h: In instantiation of ‘constexpr std::_Vector_base<_Tp, _Alloc>::~_Vector_base() [with _Tp = APT::Solver::Solved; _Alloc = std::allocator<APT::Solver::Solved>]’:
/usr/include/c++/14/bits/stl_vector.h:531:7:   required from here
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:369:49: error: invalid use of incomplete type ‘struct APT::Solver::Solved’
  369 |                       _M_impl._M_end_of_storage - _M_impl._M_start);
      |                       ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/<<PKGBUILDDIR>>/obj-arm-linux-gnueabihf/include/apt-pkg/solver3.h:88:11: note: forward declaration of ‘struct APT::Solver::Solved’
   88 |    struct Solved;
      |           ^~~~~~

0 files changed, 0 insertions, 0 deletions