* cpphash.c (_cpp_make_hashnode): Rename make_HASHNODE, now
	static.  Allocate the hashnode and its string in the same
	block of memory.
	(del_HASHNODE): Don't free h->name.
	(_cpp_lookup): If there is no entry for this string, create
	one, of type T_VOID.
	(_cpp_lookup_slot): Delete.
	* cpphash.h: Update prototypes.

	* cpplex.c (maybe_macroexpand): Check for hp->type == T_VOID,
	not hp == NULL.
	* cpplib.c (do_define, do_undef, do_pragma_poison, do_assert,
	do_unassert, cpp_defined): Use _cpp_lookup.  Don't create a
	node here, just fill in the value field properly.  "Delete"
	entries by setting the value field to T_VOID.  Check for
	hp->type == T_VOID, not hp == NULL.

	* Makefile.in (cpplib.o): Don't depend on $(HASHTAB_H).
	* cpperror.c, cppexp.c, cpplex.c, cpplib.c:  Don't include
	hashtab.h.

From-SVN: r33581