* Makefile.in: Refine dependencies.
* c-opts.c (c_common_handle_option): Do nothing for -Wimport.
* c.opt: Update help for -Wimport.
* cppfiles.c: Include hashtab.h. Update comments.
(stack_file): Read the file before updating dependencies.
(once_only_file_p): Be smarter about marking once-only files.
(_cpp_mark_file_once_only): Correct the check for existence on
the list.
(open_file_failed): Use name not path, which is NULL.
* cpphash.h: Don't include hashtab.h.
(struct _cpp_file): Remove.
(struct cpp_reader): Update.
* cppinit.c (cpp_create_reader): Don't initialize warn_import.
* cpplib.h (struct cpp_options): Remove warn_import.
(cpp_simplify_path): Remove.
From-SVN: r70045
