fix(truffle): patch posix thread detection support

because the weak symbols won't work with truffleruby, for more context
see:

- oracle/truffleruby#3031

ext/nokogiri/extconf.rb

@@ -742,6 +742,10 @@ def needs_darwin_linker_hack
     append_ldflags("-Wl,-flat_namespace")
   end
 
+  if truffle?
+    append_ldflags("-lpthread")
+  end
+
   require "yaml"
   dependencies = YAML.load_file(File.join(PACKAGE_ROOT_DIR, "dependencies.yml"))
 

patches/libxml2/0011-patch-posix-thread-detection-support.patch

@@ -0,0 +1,29 @@
+From 8cc1e13856ca509e02175552fc0f142eef46a129 Mon Sep 17 00:00:00 2001
+From: Mike Dalessio <[email protected]>
+Date: Tue, 2 May 2023 15:39:50 -0400
+Subject: [PATCH] patch posix thread detection support
+
+because the weak symbols won't work with truffleruby, for more context
+see:
+
+- https://github.com/oracle/truffleruby/issues/3031
+---
+ threads.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/threads.c b/threads.c
+index 56a917e6..c496cfbd 100644
+--- a/threads.c
++++ b/threads.c
+@@ -43,7 +43,7 @@
+
+ #elif defined(HAVE_POSIX_THREADS) && \
+       defined(__GLIBC__) && \
+-      defined(__GNUC__)
++      defined(__GNUC__) && false
+
+ /*
+  * The traditional way to check for single-threaded applications with
+-- 
+2.40.1
+