pthread_mutexattr_setkind_np() is long deprecated and should be using
pthread_mutexattr_settype() instead even on Linux. Fixes consumers
when built against glibc-2.34.

https://bugs.gentoo.org/811591
--- a/Sources/Core/System/mutex.cpp
+++ b/Sources/Core/System/mutex.cpp
@@ -37,3 +37,3 @@
 {
-#if defined(__APPLE__) || defined (__FreeBSD__) || defined(__OpenBSD__)
+#if 1
 	int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind);
@@ -55,3 +55,3 @@
 	pthread_mutexattr_init(&attr);
-	#if defined(__FreeBSD__) || defined(__APPLE__)
+	#if 1
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);