New cli-utils.h/.c function extract_info_print_args

New cli-utils.h/.c function extract_info_print_args

New cli-utils.h/.c function extract_info_print_args factorizes
the extraction of the args '[-q] [-t TYPEREGEXP] [NAMEREGEXP]'.
New cli-utils.h/.c function report_unrecognized_option_error
factorizes reporting an unknown option for a command.

These functions will be used by the commands
  info [args|functions|locals|variables]

As extract_info_print_args will be used for 'info functions|variables' which
already have the NAMEREGEXP arg, it provides a backward compatible
behaviour.

cli-utils.c has a new static function extract_arg_maybe_quoted
that extracts an argument, possibly quoted.  The behaviour of this
function is similar to the parsing done by gdb_argv.

gdb/ChangeLog
2018-10-27  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli-utils.c (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	(info_print_args_help): New function.
	(report_unrecognized_option_error): New function.
	* cli-utils.h (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	(info_print_args_help): New function.
	(report_unrecognized_option_error): New function.