Another C compatibility issue: char ** and char * are distinct types,
and strtold expects the former for its second argument.

Submitted upstream:

  <https://lists.gnu.org/archive/html/bug-bash/2023-11/msg00104.html>

diff --git a/configure.ac b/configure.ac
index 6defea0835fe8877..955c1149a8141e19 100644
--- a/configure.ac
+++ b/configure.ac
@@ -885,7 +885,7 @@ AC_CHECK_DECLS([strtold], [
 	[AC_COMPILE_IFELSE(
 		[AC_LANG_PROGRAM(
 		[[#include <stdlib.h>]],
-		[[long double r; char *foo, bar; r = strtold(foo, &bar);]]
+		[[long double r; char *foo, *bar; r = strtold(foo, &bar);]]
 	)],
 	[bash_cv_strtold_broken=no],[bash_cv_strtold_broken=yes])
         ]