* include/Makefile.am: Add ext/aligned_buffer.h
	* include/Makefile.in: Regenerate.
	* include/ext/aligned_buffer.h: New.
	* include/std/future (_Result): Use __aligned_buffer.
	* include/bits/forward_list.h (_Fwd_list_node): Likewise.
	* include/bits/shared_ptr_base.h (_Sp_counted_ptr_inplace): Likewise.
	* testsuite/20_util/shared_ptr/cons/43820_neg.cc: Adjust dg-error line
	number.

From-SVN: r197554