bug#67357: [PATCH] Fix c-ts-mode block indent when first-siblings are comments

[Eli Zaretskii]

> From: Noah Peart <noah.v.peart@gmail.com>
> Date: Fri, 24 Nov 2023 06:35:06 -0800
> Cc: dmitry@gutov.dev, casouri@gmail.com, 67357@debbugs.gnu.org
> 
> To reproduce the indentation bugs for unbracketed `else_clause`, and 
> do-while:
> 1. open a buffer and insert the following:
> 
>     int main() {
>       if (true) 
>         puts("Hello");
>       else 
>                     puts("No matched rule!"); // 1
>       do 
>         puts("Hello");
>                     while (indented_as_part_of_block);  // 2
>     }
> 
> 2. call `M-x example-setup` to configure `c-ts-mode`
> 3. `M-x indent-region` to indent the whole buffer
> You should see that the line with comment `1` has not been
> indented, and the line with comment `2` has been indented to the 
> same level as the previous line.
> 
> To reproduce the indentation bugs when comments are the first
> siblings:
> 1. open a buffer and insert:
> 
>     int main() {
>       while (true) { /* foo */
>                           if (true) { // 1
>                           puts ("Hello"); // 2
>        }
>       }
>     }
> 
> 2. call `M-x example-setup` to configure `c-ts-mode`
> 3. `M-x indent-region` to indent the whole buffer
> 
> You should see that the lines with comments `1` and `2` have
> not been indented at all.

Thanks, I see the problems now.

Let's wait for Yuan to chime in.