avoid failure to build grep.pdf due to unicode literal

[Jim Meyering]

Does someone know how to fix this properly?

I'm about to release grep-3.10, and one of the final steps in the release
process is to update th oneline web documentation, but that failed for
3.9 due to this glitch. So I've made (not yet pushed) this small change
to ensure that I can build and push the 3.10 documentation.  Of course,
I'd rather fix it properly, but that can wait until after the 3.10
release, if needed.

>From fd2a7c12b39e457fc0560d6930b68f12407ddbde Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@fb.com>
Date: Wed, 22 Mar 2023 15:25:51 -0700
Subject: [PATCH] =?UTF-8?q?doc:=20avoid=20failure=20to=20build=20grep.pdf?=
 =?UTF-8?q?=20due=20to=20=E1=BA=9E?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* doc/grep.texi (Matching Control): Elide literal ẞ, because
it would cause this command to fail (surprisingly with what an
erroneous exit code of 0) Both with 6.8 and 7.0dev:
texi2dvi --pdf -t @finalout /home/j/w/co/grep/doc/grep.texi
We'll surely find a way to restore it after release.
It would fail with this diagnostic:
  Character missing, sorry: LONG S. l.228: Unicode \
    char @u8:ẞ not defined for Texinfo
---
 doc/grep.texi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/grep.texi b/doc/grep.texi
index 4ed9782..af65e5f 100644
--- a/doc/grep.texi
+++ b/doc/grep.texi
@@ -223,7 +223,7 @@ this unusual character matches ``S'' or ``s'' even though 
uppercasing
 it yields ``S''.  Another example: the lowercase German letter ``ß''
 (U+00DF, LATIN SMALL LETTER SHARP S) is normally capitalized as the
 two-character string ``SS'' but it does not match ``SS'', and it might
-not match the uppercase letter ``ẞ'' (U+1E9E, LATIN CAPITAL LETTER
+not match the uppercase letter ``XX'' (U+1E9E, LATIN CAPITAL LETTER
 SHARP S) even though lowercasing the latter yields the former.

 @option{-y} is an obsolete synonym that is provided for compatibility.
-- 
2.40.0.rc2