feat: 适配 Lua 5.2.4 (lua_5.2.4 分支)

- lib/lua 替换为 Lua 5.2.4 官方源码; CMakeLists 补 lbitlib.c(5.2 linit 注册 bit32)、删 lutf8lib.c(5.2 无此文件)
- I/O 重定向机制改造: 5.2 无 lua_getextraspace → iopath 指针存入
  Registry 固定索引(IOPATH_REG_IDX=1), 回调经 get_iopath() 取回,
  free_lua 时释放 —— 该方案同样适用于更低版本
- typed interop 版本自适应: capture_result() 的 lua_isinteger 分支用
  #if LUA_VERSION_NUM >= 503 包裹, 5.2 及以下所有数字统一 CJT_NUM
- 测试跨版本适配: PackagePathConfig 接受 require 的两种返回语义;
  typed 数值断言 EXPECT_INT_OR_NUM 宏兼容有无 integer 子类型;
  大整数保真断言仅对 5.3+ 生效(5.2 经 double 必然丢精度)
- 验证: GTest 44/44 通过

lib/lua/llex.h

@@ -1,5 +1,5 @@
 /*
-** $Id: llex.h $
+** $Id: llex.h,v 1.72.1.1 2013/04/12 18:48:47 roberto Exp $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -7,23 +7,13 @@
 #ifndef llex_h
 #define llex_h
 
-#include <limits.h>
-
 #include "lobject.h"
 #include "lzio.h"
 
 
-/*
-** Single-char tokens (terminal symbols) are represented by their own
-** numeric code. Other tokens start at the following value.
-*/
-#define FIRST_RESERVED	(UCHAR_MAX + 1)
+#define FIRST_RESERVED	257
 
 
-#if !defined(LUA_ENV)
-#define LUA_ENV		"_ENV"
-#endif
-
 
 /*
 * WARNING: if you change the order of this enumeration,
@@ -36,19 +26,16 @@ enum RESERVED {
   TK_GOTO, TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT,
   TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE,
   /* other terminal symbols */
-  TK_IDIV, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE,
-  TK_SHL, TK_SHR,
-  TK_DBCOLON, TK_EOS,
-  TK_FLT, TK_INT, TK_NAME, TK_STRING
+  TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE, TK_DBCOLON, TK_EOS,
+  TK_NUMBER, TK_NAME, TK_STRING
 };
 
 /* number of reserved words */
-#define NUM_RESERVED	(cast_int(TK_WHILE-FIRST_RESERVED + 1))
+#define NUM_RESERVED	(cast(int, TK_WHILE-FIRST_RESERVED+1))
 
 
 typedef union {
   lua_Number r;
-  lua_Integer i;
   TString *ts;
 } SemInfo;  /* semantics information */
 
@@ -64,17 +51,17 @@ typedef struct Token {
 typedef struct LexState {
   int current;  /* current character (charint) */
   int linenumber;  /* input line counter */
-  int lastline;  /* line of last token 'consumed' */
+  int lastline;  /* line of last token `consumed' */
   Token t;  /* current token */
   Token lookahead;  /* look ahead token */
   struct FuncState *fs;  /* current function (parser) */
   struct lua_State *L;
   ZIO *z;  /* input stream */
   Mbuffer *buff;  /* buffer for tokens */
-  Table *h;  /* to avoid collection/reuse strings */
   struct Dyndata *dyd;  /* dynamic structures used by the parser */
   TString *source;  /* current source name */
   TString *envn;  /* environment variable name */
+  char decpoint;  /* locale decimal point */
 } LexState;