cpplex.c (new_buff, [...]): Use size_t everywhere, make definitions consistent with...

cpplex.c (new_buff, [...]): Use size_t everywhere, make definitions consistent with prototypes.

	* cpplex.c (new_buff, _cpp_get_buff, _cpp_extend_buff):
	Use size_t everywhere, make definitions consistent with
	prototypes.

From-SVN: r45860