Add stage 06: Lua bootstrap

The goal of stage 06 is to try parse zig synax in lua. I pulled in
lpeglable 1.2.0 and parser-gen off github to get started. All of this
needs to be cleaned up rather soon.

Lua boostraps using tcc and musl from the previous stage. Since musl
0.6.0 doesn't support dynamic linking this build of lua doesn't support
shared libraries. I couldn't easily patch musl with dlopen and friends
so instead I link statically and call deps with c api.

06/lpeglabel/lpcode.h

@@ -0,0 +1,42 @@
+/*
+** $Id: lpcode.h,v 1.7 2015/06/12 18:24:45 roberto Exp $
+*/
+
+#if !defined(lpcode_h)
+#define lpcode_h
+
+#include "lua.h"
+
+#include "lptypes.h"
+#include "lptree.h"
+#include "lpvm.h"
+
+int tocharset (TTree *tree, Charset *cs);
+int checkaux (TTree *tree, int pred);
+int fixedlenx (TTree *tree, int count, int len);
+int hascaptures (TTree *tree);
+int lp_gc (lua_State *L);
+Instruction *compile (lua_State *L, Pattern *p);
+void realloccode (lua_State *L, Pattern *p, int nsize);
+int sizei (const Instruction *i);
+
+
+#define PEnullable      0
+#define PEnofail        1
+
+/*
+** nofail(t) implies that 't' cannot fail with any input
+*/
+#define nofail(t)	checkaux(t, PEnofail)
+
+/*
+** (not nullable(t)) implies 't' cannot match without consuming
+** something
+*/
+#define nullable(t)	checkaux(t, PEnullable)
+
+#define fixedlen(t)     fixedlenx(t, 0, 0)
+
+
+
+#endif