Kernel/LibC: Implement alarm() and setitimer()

This makes vim able to start!

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

@@ -86,6 +86,7 @@ __BEGIN_DECLS
 	O(SYS_SIGACTION,		sigaction)		\
 	O(SYS_SIGPENDING,		sigpending)		\
 	O(SYS_SIGPROCMASK,		sigprocmask)	\
+	O(SYS_SETITIMER,		setitimer)		\
 
 enum Syscall
 {

userspace/libraries/LibC/sys/time.cpp

@@ -1,5 +1,7 @@
+#include <sys/syscall.h>
 #include <sys/time.h>
 #include <time.h>
+#include <unistd.h>
 
 int gettimeofday(struct timeval* __restrict tp, void* __restrict tzp)
 {
@@ -13,3 +15,8 @@ int gettimeofday(struct timeval* __restrict tp, void* __restrict tzp)
 	tp->tv_usec = ts.tv_nsec / 1000;
 	return 0;
 }
+
+int setitimer(int which, const struct itimerval* __restrict value, struct itimerval* __restrict ovalue)
+{
+	return syscall(SYS_SETITIMER, which, value, ovalue);
+}

userspace/libraries/LibC/unistd.cpp

@@ -8,6 +8,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
+#include <sys/time.h>
 #include <unistd.h>
 
 char** environ;
@@ -514,3 +515,14 @@ int access(const char* path, int amode)
 {
 	return syscall(SYS_ACCESS, path, amode);
 }
+
+unsigned alarm(unsigned seconds)
+{
+	itimerval value, ovalue;
+	value.it_value.tv_sec = seconds;
+	value.it_value.tv_usec = 0;
+	value.it_interval.tv_sec = 0;
+	value.it_interval.tv_usec = 0;
+	setitimer(ITIMER_REAL, &value, &ovalue);
+	return ovalue.it_value.tv_sec;
+}