ports: Add libxshfence port

ports/libxshmfence/build.sh

@@ -0,0 +1,11 @@
+#!/bin/bash ../install.sh
+
+NAME='libxshmfence'
+VERSION='1.3.3'
+DOWNLOAD_URL="https://www.x.org/releases/individual/lib/libxshmfence-$VERSION.tar.xz#d4a4df096aba96fea02c029ee3a44e11a47eb7f7213c1a729be83e85ec3fde10"
+CONFIG_SUB=('config.sub')
+DEPENDENCIES=('xorgproto')
+CONFIGURE_OPTIONS=(
+	'--enable-shared=yes'
+	'--enable-static=no'
+)

ports/libxshmfence/patches/0001-add-shared-library-support.patch

@@ -0,0 +1,31 @@
+diff -ruN libxshmfence-1.3.3/configure libxshmfence-1.3.3-banan_os/configure
+--- libxshmfence-1.3.3/configure	2024-12-14 04:05:14.000000000 +0200
++++ libxshmfence-1.3.3-banan_os/configure	2026-07-05 09:29:32.691762812 +0300
+@@ -6238,6 +6238,10 @@
+   lt_cv_deplibs_check_method=pass_all
+   ;;
+ 
++banan_os*)
++  lt_cv_deplibs_check_method=pass_all
++  ;;
++
+ beos*)
+   lt_cv_deplibs_check_method=pass_all
+   ;;
+@@ -11742,6 +11746,16 @@
+     ;;
+   esac
+   ;;
++ 
++banan_os*)
++  version_type=linux # correct to gnu/linux during the next big refactor
++  need_lib_prefix=no
++  need_version=no
++  library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
++  soname_spec='$libname$release$shared_ext$major'
++  dynamic_linker="$host_os DynamicLoader.so"
++  shlibpath_var=LD_LIBRARY_PATH
++  ;;
+ 
+ beos*)
+   library_names_spec='$libname$shared_ext'

ports/libxshmfence/patches/0002-implement-futex.patch

@@ -0,0 +1,22 @@
+diff -ruN libxshmfence-1.3.3/src/xshmfence_futex.h libxshmfence-1.3.3-banan_os/src/xshmfence_futex.h
+--- libxshmfence-1.3.3/src/xshmfence_futex.h	2024-12-14 04:05:01.000000000 +0200
++++ libxshmfence-1.3.3-banan_os/src/xshmfence_futex.h	2026-07-05 09:37:56.106400833 +0300
+@@ -45,6 +45,18 @@
+ 	return sys_futex(addr, UMTX_OP_WAIT_UINT, value);
+ }
+ 
++#elif defined(__banan_os__)
++
++#include <sys/futex.h>
++
++static inline int futex_wake(int32_t *addr) {
++	return futex(FUTEX_WAKE, (const uint32_t*)addr, INT_MAX, nullptr);
++}
++
++static inline int futex_wait(int32_t *addr, int32_t value) {
++	return futex(FUTEX_WAIT, (const uint32_t*)addr, value, nullptr);
++}
++
+ #else
+ 
+ #include <stdint.h>