* dllwrap.c (is_leading_underscore): New variable.
(cpu_type): New enum type.
(which_cpu): New variable.
(usage): Add new options --no-leading-underscore
and --leading-underscore.
(long_options): Likewise.
(OPTION_NO_LEADING_UNDERSCORE): New define.
(OPTION_LEADING_UNDERSCORE): Likewise.
(main): Initialize which_host, pass new options
to dlltool, do underscoring dependent on
is_leading_underscore, and do '@12' decoration
only for x86.