iswdigit, iswxdigit: Fix documentation

[Bruno Haible]

The wctype-h module does *not* fix all the problems regarding iswdigit and
iswxdigit. For this, the module 'iswdigit' or 'iswxdigit', respectively,
is needed.


2023-08-29  Bruno Haible  <bruno@clisp.org>

        iswdigit, iswxdigit: Fix documentation.
        * doc/posix-functions/iswdigit.texi: Mention the module 'iswdigit'.
        * doc/posix-functions/iswxdigit.texi: Mention the module 'iswxdigit'.

diff --git a/doc/posix-functions/iswdigit.texi 
b/doc/posix-functions/iswdigit.texi
index bdd962086d..f570504f6a 100644
--- a/doc/posix-functions/iswdigit.texi
+++ b/doc/posix-functions/iswdigit.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* 
@url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswdigit.html}
 
-Gnulib module: wctype-h
+Gnulib module: iswdigit
 
 Portability problems fixed by Gnulib:
 @itemize
diff --git a/doc/posix-functions/iswxdigit.texi 
b/doc/posix-functions/iswxdigit.texi
index 26069ec83c..3f33064117 100644
--- a/doc/posix-functions/iswxdigit.texi
+++ b/doc/posix-functions/iswxdigit.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* 
@url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswxdigit.html}
 
-Gnulib module: wctype-h
+Gnulib module: iswxdigit
 
 Portability problems fixed by Gnulib:
 @itemize