* cpphash.h: Move struct reflist, struct definition, and the
DEFINITION typedef to cpphash.c. Use 'struct definition *' in
union hashval. _cpp_free_definition takes a HASHNODE pointer.
* cpphash.c (_cpp_free_definition): Free data pointed to by
MCONST, XCONST, MACRO, and FMACRO nodes properly.
(_cpp_create_definition, del_HASHNODE): Just call
_cpp_free_definition to clear out a hashnode.
* cpplib.c (do_pragma_poison): Likewise.
From-SVN: r33536
