[librsvg: 4/9] configure: Replace obsolete AC_ISC_POSIX

[Marge Bot <marge-bot src gnome org>]

commit 6ca2cdd929f16ee94f5e86ca844ed8fa77cf4cf0
Author: Ismael Luceno <ismael iodev co uk>
Date:   Sat Sep 11 18:27:43 2021 +0200

    configure: Replace obsolete AC_ISC_POSIX
    
    Replace with an equivalent check.
    
    ISC UNIX is dead since mid 2006.
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/586>

 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index 1650cad5..9239e90c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,12 +69,13 @@ PANGO_REQUIRED=1.44.0
 dnl ===========================================================================
 
 AC_PROG_LN_S
-AC_ISC_POSIX
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_AWK
 AC_STDC_HEADERS
 AM_PROG_CC_C_O
+# Check if -lcposix is required (for ISC UNIX)
+AC_SEARCH_LIBS([strerror], [cposix])
 
 AC_C_BIGENDIAN