Kernel/LibC: Add ppoll syscall and fix poll

poll is now using its own syscall instead of wrapping aroung pselect.
This adds less overhead on top of poll and adds support for POLLHUP

userspace/libraries/LibC/include/poll.h

@@ -7,6 +7,8 @@
 
 __BEGIN_DECLS
 
+#include <signal.h>
+
 struct pollfd
 {
 	int		fd;			/* The following descriptor being polled. */
@@ -28,6 +30,7 @@ typedef unsigned long nfds_t;
 #define POLLNVAL	0x200
 
 int poll(struct pollfd fds[], nfds_t nfds, int timeout);
+int ppoll(struct pollfd fds[], nfds_t nfds, const struct timespec* timeout, const sigset_t* sigmask);
 
 __END_DECLS
 

userspace/libraries/LibC/include/sys/syscall.h

@@ -73,6 +73,7 @@ __BEGIN_DECLS
 	O(SYS_CONNECT,			connect)		\
 	O(SYS_LISTEN,			listen)			\
 	O(SYS_PSELECT,			pselect)		\
+	O(SYS_PPOLL,			ppoll)			\
 	O(SYS_TRUNCATE,			truncate)		\
 	O(SYS_SMO_CREATE,		smo_create)		\
 	O(SYS_SMO_DELETE,		smo_delete)		\