cppfiles.c (struct include_file): Update.

        * cppfiles.c (struct include_file): Update.
        (stack_include_file): Use search_from.
        (cpp_included, find_include_file): Update.
        (cpp_execute_include): Update.  ptr->name may not be
        null terminated.  Use the new search_from member variable
        of cpp_buffer.
        (_cpp_compare_file_date): Similarly.
        (search_from): New function, similiar to actual_directory.
        (actual_directory): Delete.
        (remap_filename): Update.  loc->name may not be null terminated.
        (struct file_name_list): Rename search_path.  Update.
        * cpphash.h (struct cpp_buffer): Delete actual_dir.  New members
        search_from and dir.
        (struct cpp_reader): Remove actual_dirs.
        * cppinit.c (struct cpp_pending): Update for renamed objects.
        (append_include_chain, remove_dup_dir, remove_dup_dirs,
        merge_include_chains, cpp_destroy, cpp_start_read): Similarly.
        * cpplib.h (struct cpp_options): Similarly.

From-SVN: r40178