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/lptypes.h

@@ -0,0 +1,171 @@
+/*
+** $Id: lptypes.h,v 1.14 2015/09/28 17:17:41 roberto Exp $
+** LPeg - PEG pattern matching for Lua
+** Copyright 2007-2015, Lua.org & PUC-Rio  (see 'lpeg.html' for license)
+** written by Roberto Ierusalimschy
+*/
+
+#if !defined(lptypes_h)
+#define lptypes_h
+
+
+#if !defined(LPEG_DEBUG)
+#define NDEBUG
+#endif
+
+#include <assert.h>
+#include <limits.h>
+
+#include "lua.h"
+
+
+#define VERSION         "1.0.0"
+
+
+#define PATTERN_T	"lpeg-pattern"
+#define MAXSTACKIDX	"lpeg-maxstack"
+
+
+/*
+** compatibility with Lua 5.1
+*/
+#if (LUA_VERSION_NUM == 501)
+
+#define lp_equal	lua_equal
+
+#define lua_getuservalue	lua_getfenv
+#define lua_setuservalue	lua_setfenv
+
+#define lua_rawlen		lua_objlen
+
+#define luaL_setfuncs(L,f,n)	luaL_register(L,NULL,f)
+#define luaL_newlib(L,f)	luaL_register(L,"lpeg",f)
+
+#endif
+
+
+#if !defined(lp_equal)
+#define lp_equal(L,idx1,idx2)  lua_compare(L,(idx1),(idx2),LUA_OPEQ)
+#endif
+
+
+/* default maximum size for call/backtrack stack */
+#if !defined(MAXBACK)
+#define MAXBACK         400
+#endif
+
+
+/* maximum number of rules in a grammar */
+#if !defined(MAXRULES)
+#define MAXRULES        1000
+#endif
+
+
+
+/* initial size for capture's list */
+#define INITCAPSIZE	32
+
+
+/* index, on Lua stack, for subject */
+#define SUBJIDX		2
+
+/* number of fixed arguments to 'match' (before capture arguments) */
+#define FIXEDARGS	3
+
+/* index, on Lua stack, for capture list */
+#define caplistidx(ptop)	((ptop) + 2)
+
+/* index, on Lua stack, for pattern's ktable */
+#define ktableidx(ptop)		((ptop) + 3)
+
+/* index, on Lua stack, for backtracking stack */
+#define stackidx(ptop)	((ptop) + 4)
+
+
+
+typedef unsigned char byte;
+
+
+#define BITSPERCHAR		8
+
+#define CHARSETSIZE		((UCHAR_MAX/BITSPERCHAR) + 1)
+
+
+
+typedef struct Charset {
+  byte cs[CHARSETSIZE];
+} Charset;
+
+
+
+#define loopset(v,b)    { int v; for (v = 0; v < CHARSETSIZE; v++) {b;} }
+
+/* access to charset */
+#define treebuffer(t)      ((byte *)((t) + 1))
+
+/* number of slots needed for 'n' bytes */
+#define bytes2slots(n)  (((n) - 1) / sizeof(TTree) + 1)
+
+/* set 'b' bit in charset 'cs' */
+#define setchar(cs,b)   ((cs)[(b) >> 3] |= (1 << ((b) & 7)))
+
+
+/*
+** in capture instructions, 'kind' of capture and its offset are
+** packed in field 'aux', 4 bits for each
+*/
+#define getkind(op)		((op)->i.aux & 0xF)
+#define getoff(op)		(((op)->i.aux >> 4) & 0xF)
+#define joinkindoff(k,o)	((k) | ((o) << 4))
+
+#define MAXOFF		0xF
+#define MAXAUX		0xFF
+
+
+/* maximum number of bytes to look behind */
+#define MAXBEHIND	MAXAUX
+
+
+/* maximum size (in elements) for a pattern */
+#define MAXPATTSIZE	(SHRT_MAX - 10)
+
+
+/* size (in elements) for an instruction plus extra l bytes */
+#define instsize(l)  (((l) + sizeof(Instruction) - 1)/sizeof(Instruction) + 1)
+
+
+/* size (in elements) for a ISet instruction */
+#define CHARSETINSTSIZE		instsize(CHARSETSIZE)
+
+/* size (in elements) for a IFunc instruction */
+#define funcinstsize(p)		((p)->i.aux + 2)
+
+
+
+#define testchar(st,c)	(((int)(st)[((c) >> 3)] & (1 << ((c) & 7))))
+
+/* labeled failure begin */
+#define MAXLABELS (UCHAR_MAX + 1)
+
+#define LABELSETSIZE CHARSETSIZE
+
+typedef Charset Labelset;
+
+#define setlabel setchar
+
+#define testlabel testchar
+
+/* access to labelset */
+#define treelabelset(t)      ((byte *)((t) + (t)->u.s.plab))
+
+#define IDXLFAIL 0
+
+#define LFAIL 0
+
+/* update the farthest failure */
+#define updatefarthest(s1,s2) { if ((s2) > (s1)) s1 = s2; }
+
+/* labeled failure end */
+
+#endif
+