* cppfiles.c (hash_IHASH): Just return i->hash.
(cpp_included): Set dummy.hash using _cpp_calc_hash. Use
htab_find_with_hash.
(cpp_read_file): Likewise.
(find_include_file): Likewise. Properly initialize
ih->nshort. Share ih->name and ih->nshort if possible.
* cpphash.c (_cpp_calc_hash): New function.
(hash_HASHNODE): Just return h->hash.
(_cpp_lookup): Set dummy.hash using _cpp_calc_hash. Use
htab_find_with_hash.
* cpphash.h: Prototype _cpp_calc_hash.
* cppinit.c (initialize_builtins): Provide a valid hash
to _cpp_make_hashnode, using _cpp_calc_hash.
* cpphash.c (collect_expansion): # is not a special character
in object-like macros. In -traditional mode, /**/ is not
token paste at the beginning or end of the line.
* cpplib.c (do_include, do_import, do_include_next): If
parse_include fails, return immediately.