bug#61893: 29.0.60; Indentation in c-ts-mode broken again

[Eli Zaretskii <eliz@gnu.org>]

> From: Yuan Fu <casouri@gmail.com>
> Date: Sat, 4 Mar 2023 15:03:46 -0800
> Cc: Eli Zaretskii <eliz@gnu.org>,
>  Daniel Martín <mardani29@yahoo.es>,
>  61893@debbugs.gnu.org
> 
> >>>> The elif directive’s and subsequent directives aren’t indented properly. Looking at the parsed tree, the elif directives are nested in the if directive, and the nesting can be arbitrarily deep. We probably need a custom function rather than great-grand-parent to find the anchor, like a function that keeps going up the tree until the node isn’t a preproc directive anymore.
> >>>> 
> >>>> Yuan
> >>> 
> >>> Yeah, you're right. I'll see what I can do, but bandwidth is a little low at the moment, so if you have some extra time, don't hesitate to improve it :)
> >> 
> >> Absolutely, I’ll work on it. 
> >> 
> >> Yuan
> > 
> > Thanks :)
> 
> Done!

Thanks.

Some problems still remain.

Line 1761 of dispnew.c: type "C-e RET" -- point goes to column 7
instead of the expected column 2.

Line 3381 of dispnew.c: type "C-e RET" -- point goes to the correct
column, but line 3381 is reindented incorrectly.

Line 6611 of dispnew.e: type "C-e RET" -- point goes to column 0
instead of the expected column 2.  If you type "C-e RET" on the next
line 6612, point goes to column 0 and the line is reindented
incorrectly.

Line 13925 of xdisp.c: type "C-e RET" -- point goes to column 33(!)
and line 13925 is reindented incorrectly.

Lines 34529 and 34530 of xdisp.c: "C-e RET" produces incorrect column
of point and reindents line 34530.