Fix compilation errors with older C compilers (regression 2025-12-19).

* gnulib-local/lib/xerror.c (multiline_internal): Add a semicolon between
a label and a declaration.
* gettext-tools/src/write-po.c (wrap): Likewise.
* gettext-tools/src/format-go.c (format_parse): Likewise.

gettext-tools/src/format-go.c

@@ -384,7 +384,7 @@ format_parse (const char *format, bool translated, char *fdi,
               }
           }
 
-       parse_specifier:
+       parse_specifier: ;
         /* Parse the specifier.  */
         enum format_arg_type type;
         switch (*format)

gettext-tools/src/write-po.c

@@ -993,7 +993,7 @@ wrap (const message_ty *mp, ostream_t stream,
       /* Adjust for indentation of subsequent lines.  */
       width -= startcol_after_break;
 
-    recompute:
+    recompute: ;
       /* The line starts with different things depending on whether it
          is the first line, and if we are using the indented style.
          See INDENT-F.  */

gnulib-local/lib/xerror.c

@@ -67,7 +67,7 @@ multiline_internal (char *prefix, size_t prefix_width, char *message)
       for (size_t i = width; i > 0; i--)
         putc (' ', stderr);
 
-    after_indent:
+    after_indent: ;
       const char *np = strchr (cp, '\n');
 
       if (np == NULL || np[1] == '\0')