AX_PTHREAD requires _REENTRANT to confirm that pthread support is enabled.
Solaris 11.4 headers no longer use the macro, and GCC 16 therefore no
longer defines it for -pthread.
Detect XPG7 support in the target headers and require _REENTRANT only on
older Solaris releases. The existing pthread compile and link test remains
the final capability check.
This follows the canonical Autoconf Archive change:
https://github.com/autoconf-archive/autoconf-archive/pull/341
Regenerate configure with Autoconf 2.71.
Tested on Solaris 11.4 with GCC 15.2 and GCC 16.1. The Autoconf Archive
change was also tested on Solaris 11.3.
Co-authored-by: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
Use vanilla m4 files with known source. Prepared for possible removal at
build time if the system already has autoconf-archive source present.
Switch to AX_PKG_SWIG macro for versioned or unversioned swig detection.
patch to it to not fail when -Werror is also specified, from the
autoconf-archives.
git-svn-id: file:///svn/unbound/trunk@2904 be551aaa-1e26-0410-a405-d3ace91eadb9
