Fixed a memory leak where the screen would not be freed when used with the debugger
diff --git a/common.h b/common.h
index e1e297f..1540ff9 100644
--- a/common.h
+++ b/common.h
@@ -28,6 +28,7 @@
 extern unsigned g_catch_len;
 
 void throw_(const char *msg, const char *file, unsigned int line);
+void unwind();
 void catch_(handle_t hdl, intptr_t arg);
 
 #define THROW(msg) throw_(msg, __FILENAME__, __LINE__)