(long_options): Add "debug" and "linker".
(main): Handle -d and -l arguments. Make command line input and
output files optional. Parse the command file before opening the
BFD's, which requires storing more information in local variables.
If INPUT names multiple files, link them together. Use OUTPUT for
the output file name if not named on command line.
(show_usage): Changed for new options.
(link_inputs): New function to automatically invoke linker to
handle multiple INPUT files.
(choose_temp_base_try, choose_temp_base, pexecute): New functions,
mostly copied from gcc/gcc.c.
* nlmconv.h (input_files, output_file): Declare.
* nlmheader.y (input_files, output_file): Define.
(command): Support INPUT with a string_list argument. Support
OUTPUT.
(string_list): Renamed from module_list.
* Makefile.in (nlmconv.o): Define LD_NAME based on
program_transform_name.
Fixes PR 3974.
