in_place_stop_token copy constructor/assignment and destructor

[vasama]

The wording for in_place_stop_token is missing copy constructor and copy assignment and contains a destructor the effects of which are not described.

The reference implementation for in_place_stop_token provides trivial copy, trivial destructor and linear move. This is clearly not according to the specification.

Assuming the intent is for in_place_stop_token to be trivially copyable, the special member functions for copying should be specified defaulted and the destructor removed.