[PATCH 02/21] Configure: regenerate for autoconf 2.71

[Joseph Myers]

On Tue, 20 Jun 2023, Frédéric Bérat via Libc-alpha wrote:

> Update configure.ac to enable support for autoconf 2.71, and autoreconf
> to integrate new enable-fortify-source option.

Please don't mix an autoconf version change into a patch series with 
another purpose.  If you wish to propose an autoconf version change, do it 
in a standalone patch with its own justification, making sure to update 
manual/install.texi, regenerate INSTALL and regenerate any configure / 
preconfigure fragments affected by the change (or say explicitly if such 
fragments are unchanged after regeneration).

-- 
Joseph S. Myers
joseph@codesourcery.com