* include/bits/unique_ptr.h (__uniq_ptr_impl): Add move constructor,
move assignment operator.
(__uniq_ptr_impl::release(), __uniq_ptr_impl::reset(pointer)): Add.
(__uniq_ptr_data): New class template with conditionally deleted
special members.
(unique_ptr, unique_ptr<T[], D>): Change type of data member from
__uniq_ptr_impl<T, D> to __uniq_ptr_data<T, D>. Define move
constructor and move assignment operator as defaulted.
(unique_ptr::release(), unique_ptr<T[], D>::release()): Forward to
__uniq_ptr_impl::release().
(unique_ptr::reset(pointer), unique_ptr<T[], D>::reset<U>(U)): Forward
to __uniq_ptr_impl::reset(pointer).
* python/libstdcxx/v6/printers.py (UniquePointerPrinter.__init__):
Check for new __uniq_ptr_data type.
* testsuite/20_util/unique_ptr/dr2899.cc: New test.
From-SVN: r271158
