* cpphash.h (struct cpp_buff): Make unsigned.
	(_cpp_get_buff): Take length of size_t.
	(_cpp_unaligned_alloc): New.
	(BUFF_ROOM, BUFF_FRONT, BUFF_LIMIT): New.
	(struct cpp_reader): Remove ident_pool.  Add u_buff.
	* cppinit.c (cpp_create_reader): Initialize u_buff, not ident_pool.
	(cpp_destroy): Destroy u_buff, not ident_pool.
	* cpplex.c (parse_number, parse_string, save_comment,
	cpp_token_as_text): Update to use the unaligned buffer.
	(new_buff): Make unsigned.
	(_cpp_unaligned_alloc): New.
	* cpplib.c (glue_header_name): Update to use the unaligned buffer.
	* cppmacro.c (new_number_token, builtin_macro, stringify_arg):
	Similarly.
	(collect_args): Make unsigned.

From-SVN: r45858