Deque code cleanup and optimizations

[François Dumont]

Hi

 Â Â Â  This patch implements a number of simplifications and optimizations 
already done to other containers like std::vector

- Default default and move constructors

- The std::swap optimization

- The construction always equal allocator optimization

- Shortcuts on method calls.

 Â Â Â  I remove several _M_map != nullptr checks cause in current 
implementation it can't be null. I have several patches following this 
one to support it but in this case we will be using a different code path.

 Â Â Â  Now that we take shortcuts in several methods in C++11 there are 
some that are simply unused in C++11 mode. For the moment I kept them as 
long as we are not in versioned namespace scope in order to maintain abi 
compatibility, I wonder if I really need to consider abi 
backward-compatibility here ?

 Â Â Â  * include/bits/stl_deque.h (_Deque_base(_Deque_base&&, false_type)):
 Â Â Â  Make private.
 Â Â Â  (_Deque_base(_Deque_base&&, true_type)): Likewise. Remove _M_map check.
 Â Â Â  (_Deque_base(_Deque_base&&, const allocator_type&)): New.
 Â Â Â  (_Deque_base(_Deque_base&&, const allocator_type&, size_t)): Remove
 Â Â Â  _M_map check.
 Â Â Â  (_Deque_base::_Deque_impl_data): New.
 Â Â Â  (_Deque_base::_Deque_impl): Inherit latter.
 Â Â Â  (_Deque_base::_Deque_impl::_M_swap_data): Move...
 Â Â Â  (_Deque_base::_Deque_impl_data::_M_swap_data): ... here.
 Â Â Â  (_Deque_base::_Deque_impl()): Add noexcept qualification.
 Â Â Â  (_Deque_base::_Deque_impl(_Deque_impl&&, _Tp_alloc_type&&)): New.
 Â Â Â  (_Deque_base::_Deque_impl::_M_get_Tp_allocator()): Remove static_cast.
 Â Â Â  (_Deque_base::_Deque_impl::_M_move_impl()): Remove _M_impl._M_map 
check.
 Â Â Â  (deque<>::deque()): Default.
 Â Â Â  (deque<>::deque(deque&&)): Default.
 Â Â Â  (deque<>::deque(deque&&, const allocator_type&, false_type)): New.
 Â Â Â  (deque<>::deque(deque&&, const allocator_type&, true_type)): New.
 Â Â Â  (deque<>::deque(deque&&, const allocator_type&)): Delegate to latters.
 Â Â Â  (deque<>::deque<_It>(_It, _It, const allocator_type&)): Use
 Â Â Â  _M_range_initialize.
 Â Â Â  (deque<>::assign<_It>(_It, _It)): Use _M_assign_aux.
 Â Â Â  (deque<>::resize(size_type, const value_type&)): Share a single
 Â Â Â  implementation.
 Â Â Â  (deque<>::insert<_It>(const_iterator, _It, _It)): Use
 Â Â Â  _M_range_insert_aux.
 Â Â Â  [__cplusplus >= 201103L && 
_GLIBCXX_INLINE_VERSION](_M_initialize_dispatch):
 Â Â Â  Remove.
 Â Â Â  [__cplusplus >= 201103L && 
_GLIBCXX_INLINE_VERSION](_M_assign_dispatch):
 Â Â Â  Remove.
 Â Â Â  [__cplusplus >= 201103L && 
_GLIBCXX_INLINE_VERSION](_M_insert_dispatch):
 Â Â Â  Remove.
 Â Â Â  * testsuite/23_containers/deque/allocator/default_init.cc: New.

Tested under Linux x86_64 normal and debug modes.

Ok to commit ?

François

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