Added missing/wrong includes.

diff --git a/if1632/builtin.c b/if1632/builtin.c
index a986ff6..421fbca 100644
--- a/if1632/builtin.c
+++ b/if1632/builtin.c
@@ -22,6 +22,7 @@
 #include "snoop.h"
 #include "task.h"
 #include "debug.h"
+#include "toolhelp.h"
 
 DEFAULT_DEBUG_CHANNEL(module)