libstree: build fixes

Update config.{guess,sub} to recognise arm64, fix implicit declaration
error in configure.

science/libstree/Portfile

@@ -6,19 +6,28 @@ name                libstree
 version             0.4.2
 categories          science
 license             MIT
-platforms           darwin
 maintainers         nomaintainer
 
 description         generic suffix tree implementation, written in C
 
-long_description    ${description}
+long_description    {*}${description}
 
 homepage            http://www.cl.cam.ac.uk/~cpk25/libstree/
 master_sites        http://www.cl.cam.ac.uk/~cpk25/downloads/
 
 checksums           sha1    b35bc18fbbc43bec1415bc1d884708e1df7bf2c6
 
-patchfiles          patch-src__lst_string.h
+patchfiles          implicit.patch \
+                    patch-src__lst_string.h
+
+# Update config.guess and config.sub to be able to build on arm64.
+depends_build-append    port:automake
+post-patch {
+    set automake_dirs [glob -directory ${prefix}/share automake-*]
+    set automake_dir [lindex [lsort -command vercmp $automake_dirs] end]
+    copy -force ${automake_dir}/config.guess ${automake_dir}/config.sub \
+        ${worksrcpath}
+}
 
 post-build {
     system "cd ${worksrcpath}/src/.libs && \

science/libstree/files/implicit.patch

@@ -0,0 +1,20 @@
+--- configure.orig	2006-03-02 01:07:26
++++ configure	2025-09-15 07:36:36
+@@ -4202,14 +4202,14 @@
+ 
+ #define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
+ int
+-main ()
++main (void)
+ {
+   int i;
+   for (i = 0; i < 256; i++)
+     if (XOR (islower (i), ISLOWER (i))
+ 	|| toupper (i) != TOUPPER (i))
+-      exit(2);
+-  exit (0);
++      return (2);
++  return (0);
+ }
+ _ACEOF
+ rm -f conftest$ac_exeext