Define std::__to_address helper

Define std::__to_address helper

	* include/bits/allocated_ptr.h (__allocated_ptr::get): Use
	__to_address.
	(__allocated_ptr::_S_raw_ptr): Remove.
	* include/bits/forward_list.h (_Fwd_list_base::_M_get_node): Use
	__to_address.
	* include/bits/hashtable_policy.h (_Hashtable_alloc): Likewise.
	* include/bits/ptr_traits.h (__to_address): Define new function
	template.
	* include/bits/shared_ptr_base.h (__shared_ptr): Use __to_address.
	(__shared_ptr::_S_raw_ptr): Remove.
	* include/bits/stl_vector.h [__cplusplus >= 201103L]
	(vector::_M_data_ptr): Use __to_address.
	[__cplusplus < 201103L] (vector::_M_data_ptr): Don't dereference
	possibly invalid pointers.
	* include/ext/alloc_traits.h (__alloc_traits::construct)
	(__alloc_traits::destroy): Use __to_address.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252055 138bc75d-0d04-0410-961f-82ee72b054a4