Add gettimeofday() syscall and LibC wrappers gettimeofday() and time().

This only has second accuracy right now, I'll work out subseconds later.

LibC/time.cpp

@@ -0,0 +1,21 @@
+#include "time.h"
+#include "errno.h"
+#include <Kernel/Syscall.h>
+
+extern "C" {
+
+time_t time(time_t* tloc)
+{
+    timeval tv;
+    if (gettimeofday(&tv) < 0)
+        return (time_t)-1;
+    return tv.tv_sec;
+}
+
+int gettimeofday(timeval* tv)
+{
+    int rc = Syscall::invoke(Syscall::PosixGettimeofday, (dword)tv);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+}