driver: replace getopt with cxxopts, replace -B, clean up help

[widlarizer]

Implements #4580.

In this PR I'm adding the cxxopts header-only library as a submodule. This allows me to introduce long option aliases such as --quiet for -q. Since -B was undocummented and is assumed not broadly used, I'm replacing it with --perffile. Behaviour of -- is retained as implemented in #3973. The behavior of yosys -help being special cased not to be equivalent to yosys -h -e -l -p is also retained. Help string indentation isn't retained since we're letting cxxopts generate it. Argument names like logfile are converted for consistency into <logfile> which is then used as is broadly the POSIX/GNU convention. Long options don't have to match the first letter of the short option if it's more logical that way, for example, -m is --plugin, I also changed the help string to load the specified <plugin> module since it was colliding with the concept of the HDL top module. The HDL top module selection option is now -r and --top and its help is elaborate the specified HDL <top> module. There's more minor differences in wording

The error reporting the usage of an unimplemented option such as -z now mentions that option. Before: Run 'yosys -h' for help. After:

Error parsing options: Option 'z' does not exist
Run 'yosys --help' for help.

From this PR onward, it should decision whether a flag gets to hog the top level namespace since we now have an alternative. On the other hand, it should make it easier to experiment by adding long-only options.

• Manually test on Windows

[widlarizer]

I've sorted the options into help groups. Bit iffy on the developer vs logging side. Current help string output:

Yosys Open SYnthesis Suite
Usage:
  ./yosys [OPTION...] [<infile> [..]]

 operation options:
  -b, --backend <backend>       use <backend> for the output file specified on the command line
  -f, --frontend <frontend>     use <frontend> for the input files on the command line
  -s, --scriptfile <scriptfile>
                                execute the commands in <scriptfile>
  -c, --tcl-scriptfile <tcl_scriptfile>
                                execute the commands in the TCL <tcl_scriptfile> (see 'help tcl' for details)
  -C, --tcl-interactive         enters TCL interactive shell mode
  -p, --commands <commands>     execute <commands> (to chain commands, separate them with semicolon + whitespace: 'cmd1; cmd2')
  -r, --top <top>               elaborate the specified HDL <top> module
  -m, --plugin <plugin>         load the specified <plugin> module
  -D, --define <define>[=<value>]
                                set the specified Verilog define to <value> if supplied via command "read -define"
  -S, --synth                   shortcut for calling the "synth" command, a default script for transforming the Verilog input to a gate-level netlist. For example: yosys -o output.blif -S input.v For more complex synthesis jobs it is recommended to use the read_* and write_* commands in a script file instead of specifying input and output files on the command line.
  -H                            print the command list
  -h, --help [<command>]        print this help message. If given, print help for <command>.
  -V, --version                 print version information and exit

 logging options:
  -Q                            suppress printing of banner (copyright, disclaimer, version)
  -T                            suppress printing of footer (log hash, version, timing statistics)
  -q, --quiet                   quiet operation. Only write warnings and error messages to console. Use this option twice to also quiet warning messages
  -v, --verbose <level>         print log headers up to <level> to the console. Implies -q for everything except the 'End of script.' message.
  -t, --timestamp               annotate all log messages with a time stamp
  -d, --detailed-timing         print more detailed timing stats at exit
  -l, --logfile <logfile>       write log messages to <logfile>
  -L, --line-buffered-logfile <logfile>
                                like -l but open <logfile> in line buffered mode
  -o, --outfile <outfile>       write the design to <outfile> on exit
  -P, --dump-design <header_id>[:<filename>]
                                dump the design when printing the specified log header to a file. yosys_dump_<header_id>.il is used as filename if none is specified. Use 'ALL' as <header_id> to dump at every header.
  -W, --warning-as-warning <regex>
                                print a warning for all log messages matching <regex>
  -w, --warning-as-message <regex>
                                if a warning message matches <regex>, it is printed as regular message instead
  -e, --warning-as-error <regex>
                                if a warning message matches <regex>, it is printed as error message instead
  -E, --deps-file <depsfile>    write a Makefile dependencies file <depsfile> with input and output file names

 developer options:
  -X, --trace                   enable tracing of core data structure changes. for debugging
  -M, --randomize-pointers      will slightly randomize allocated pointer addresses. for debugging
  -A, --abort                   will call abort() at the end of the script. for debugging
  -x, --experimental <feature>  do not print warnings for the experimental <feature>
  -g, --debug                   globally enable debug log messages
      --perffile <perffile>     write a JSON performance log to <perffile>

EDIT: updated to match latest commit

[mmicko]

Please switch to https link for submodule, could create issues later if not

[widlarizer]

dang, ok