Fix configure check and port configure script to C99

Related to:

  <https://fedoraproject.org/wiki/Changes/PortingToModernC>
  <https://fedoraproject.org/wiki/Toolchain/PortingToModernC>

bind-9.19-configure-c99.patch

@@ -0,0 +1,34 @@
+commit 5d33446145e7602c8348972dea1bb4e88d84d27f
+Author: Arjun Shankar <arjun@redhat.com>
+Date:   Tue May 2 13:58:18 2023 +0200
+
+    configure: Fix __builtin_mul_overflow() compiler support check
+    
+    `UINT64_C(UINT64_MAX)' is redundant and leads to a compilation error
+    since UINT64_C involves token concatenation, causing the check to fail.
+    
+    This change fixes that by using UINT64_MAX directly, and including the
+    appropriate header.
+    
+    Signed-off-by: Arjun Shankar <arjun@redhat.com>
+
+diff --git a/configure.ac b/configure.ac
+index e7f59f8e6d..7b6446a1ab 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -1247,8 +1247,10 @@ AC_LINK_IFELSE(
+ AC_MSG_CHECKING([compiler support for __builtin_mul_overflow()])
+ AC_LINK_IFELSE(
+   [AC_LANG_PROGRAM(
+-     [[#include <limits.h>]],
+-     [[return (__builtin_mul_overflow(UINT64_C(UINT64_MAX), UINT64_C(UINT64_MAX), &(uint64_t){ 0 }));]]
++     [[#include <limits.h>
++       #include <stdint.h>
++     ]],
++     [[return (__builtin_mul_overflow(UINT64_MAX, UINT64_MAX, &(uint64_t){ 0 }));]]
+    )],
+   [AC_MSG_RESULT([yes])
+    AC_DEFINE([HAVE_BUILTIN_MUL_OVERFLOW], [1], [define if the compiler supports __builtin_mul_overflow().])
+-- 
+2.40.1
+

bind9-next.spec

@@ -94,6 +94,8 @@ Source49: named-chroot.files
 # Red Hat specific documentation is not relevant to upstream
 Patch1: bind-9.16-redhat_doc.patch
 
+Patch2: bind-9.19-configure-c99.patch
+
 %{?systemd_ordering}
 Requires:       coreutils
 Requires(pre):  shadow-utils