fx: implement mutex support

fx/sys/apple/mutex.c

@@ -0,0 +1,17 @@
+#include <fx/thread.h>
+#include <pthread.h>
+
+bool fx_mutex_lock(fx_mutex *mut)
+{
+	return pthread_mutex_lock(mut) == 0;
+}
+
+bool fx_mutex_trylock(fx_mutex *mut)
+{
+	return pthread_mutex_trylock(mut) == 0;
+}
+
+bool fx_mutex_unlock(fx_mutex *mut)
+{
+	return pthread_mutex_trylock(mut) == 0;
+}

fx/sys/linux/mutex.c

@@ -0,0 +1,17 @@
+#include <fx/thread.h>
+#include <pthread.h>
+
+bool fx_mutex_lock(fx_mutex *mut)
+{
+	return pthread_mutex_lock(mut) == 0;
+}
+
+bool fx_mutex_trylock(fx_mutex *mut)
+{
+	return pthread_mutex_trylock(mut) == 0;
+}
+
+bool fx_mutex_unlock(fx_mutex *mut)
+{
+	return pthread_mutex_trylock(mut) == 0;
+}