Finish stack walking, mark+sweep for GC
diff --git a/src/lisp/plat/plat.h b/src/lisp/plat/plat.h
index f10676c..3640005 100644
--- a/src/lisp/plat/plat.h
+++ b/src/lisp/plat/plat.h
@@ -12,3 +12,5 @@
 void free_aligned(void *addr);
 
 void *link(dasm_State **Dst);
+
+#define THREAD_LOCAL