bug#64590: Patch: fix gud-go in gdb-mi.el

[Eli Zaretskii]

> From: Wang Diancheng <dianchengwang@gmail.com>
> Date: Thu, 13 Jul 2023 12:40:58 +0800
> 
> document of gud-go says "Start or continue execution.  Use a prefix to
> specify arguments." but it always prompts for program arguments
> regardless of whether "C-u" is pressed because arg is numeric prefix
> here.

Right, gud-def specifies '(interactive "p")'.

> The attachment is a patch to change gud-go just prompts if
> prefix is not 1.

This will have the subtlety that "C-u 1 C-v" will fail to ask for
program arguments.  Shouldn't we instead look at current-prefix-arg?

Thanks.