Kernel: Make all futexes shared

Some stuff tries to use shared futexes so make them all shared. Private
futexes would be faster as they are process specific but supporting both
would need some reworks

kernel/include/kernel/Process.h

@@ -350,14 +350,6 @@ namespace Kernel
 		BAN::UniqPtr<PageTable> m_page_table;
 		BAN::RefPtr<TTY> m_controlling_terminal;
 
-		struct futex_t
-		{
-			ThreadBlocker blocker;
-			uint32_t waiters { 0 };
-			uint32_t to_wakeup { 0 };
-		};
-		BAN::HashMap<paddr_t, BAN::UniqPtr<futex_t>> m_futexes;
-
 		friend class Thread;
 	};