[PATCH] gold: Implement --long-plt flag.

[Cary Coutant]

>  template<bool big_endian>
>  void
> -Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
> +Output_data_plt_arm_short<big_endian>::do_fill_plt_entry(
>      unsigned char* pov,
>      Arm_address got_address,
>      Arm_address plt_address,

Please fix this routine to issue an error message, suggesting the use
of --long-plt, if the offset overflows the standard PLT.

> +  DEFINE_bool(long_plt, options::TWO_DASHES, '\0', false,
> +             N_("(ARM only) Generate long PLT entries."),
> +             N_("(ARM only) Do not generate long PLT entries."));

Help strings should not end with periods. (Yeah, there are some already there.)

This is OK with those changes.

-cary