* cpphash.h (POOL_ALIGN, POOL_FRONT, POOL_LIMIT, POOL_BASE,
	POOL_SIZE, POOL_ROOM, POOL_COMMIT, struct cpp_chunk,
	struct cpp_pool, _cpp_init_pool, _cpp_free_pool, _cpp_pool_reserve,
	_cpp_pool_alloc, _cpp_next_chunk): Remove.
	(_cpp_extend_buff, BUFF_ROOM): Update.
	(_cpp_append_extend_buff): New.
	(struct cpp_reader): Remove macro_pool, add a_buff.
	* cppinit.c (cpp_create_reader): Initialize a_buff, instead of
	macro_pool.
	(cpp_destroy): Free a_buff instead of macro_pool.
	* cpplex.c (new_chunk, chunk_suitable, _cpp_next_chunk,
	new_chunk, _cpp_init_pool, _cpp_free_pool, _cpp_pool_reserve,
	_cpp_pool_alloc, ): Remove.
	(parse_number, parse_string): Update use of _cpp_extend_buff.
	(_cpp_extend_buff): Update.
	(_cpp_append_extend_buff, cpp_aligned_alloc): New.
	* cpplib.c (glue_header_name, parse_answer):
	Update use of _cpp_extend_buff.
	(cpp_register_pragma, cpp_register_pragma_space): Use
	_cpp_aligned_alloc.
	(do_assert, do_unassert): Check for EOL, update.
	* cppmacro.c (stringify_arg, collect_args): Update to use
	_cpp_extend_buff and _cpp_append_extend_buff.
	(save_parameter, parse_params, alloc_expansion_token,
	_cpp_create_definition): Rework memory management.

	* gcc.dg/cpp/redef2.c: Add test.

From-SVN: r45899