* include/std/functional (_Bind_simple, _Bind_simple_helper)
(__bind_simple): Remove.
* include/std/future: Include <bits/invoke.h> instead of <functional>.
(__future_base::_Task_state::_M_run)
(__future_base::_Task_state::_M_run_delayed): Use lambda expressions
instead of __bind_simple.
(__future_base::_Task_state::_S_maybe_wrap_ref): Remove.
(async): Use thread::__make_invoker instead of __bind_simple.
* include/std/thread: Include <tuple> and <bits/invoke.h> instead of
<functional>.
(thread::_Invoker, thread::__make_invoker): Define helpers to do
INVOKE(DECAY_COPY(f), DECAY_COPY(args)...).
From-SVN: r241093
5579170b40