Added 6 parameters syscalls for zen

std/os/zen.zig

@@ -103,3 +103,17 @@ pub inline fn syscall5(number: usize, arg1: usize, arg2: usize, arg3: usize,
             [arg4] "{esi}" (arg4),
             [arg5] "{edi}" (arg5));
 }
+
+pub inline fn syscall6(number: usize, arg1: usize, arg2: usize, arg3: usize,
+    arg4: usize, arg5: usize, arg6: usize) usize
+{
+    return asm volatile ("int $0x80"
+        : [ret] "={eax}" (-> usize)
+        : [number] "{eax}" (number),
+            [arg1] "{ecx}" (arg1),
+            [arg2] "{edx}" (arg2),
+            [arg3] "{ebx}" (arg3),
+            [arg4] "{esi}" (arg4),
+            [arg5] "{edi}" (arg5),
+            [arg6] "{ebp}" (arg6));
+}