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/lfunc.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.h $
+** $Id: lfunc.h,v 2.8.1.1 2013/04/12 18:48:47 roberto Exp $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -11,52 +11,21 @@
 #include "lobject.h"
 
 
-#define sizeCclosure(n)	(cast_int(offsetof(CClosure, upvalue)) + \
-                         cast_int(sizeof(TValue)) * (n))
+#define sizeCclosure(n)	(cast(int, sizeof(CClosure)) + \
+                         cast(int, sizeof(TValue)*((n)-1)))
 
-#define sizeLclosure(n)	(cast_int(offsetof(LClosure, upvals)) + \
-                         cast_int(sizeof(TValue *)) * (n))
-
-
-/* test whether thread is in 'twups' list */
-#define isintwups(L)	(L->twups != L)
-
-
-/*
-** maximum number of upvalues in a closure (both C and Lua). (Value
-** must fit in a VM register.)
-*/
-#define MAXUPVAL	255
-
-
-#define upisopen(up)	((up)->v.p != &(up)->u.value)
-
-
-#define uplevel(up)	check_exp(upisopen(up), cast(StkId, (up)->v.p))
-
-
-/*
-** maximum number of misses before giving up the cache of closures
-** in prototypes
-*/
-#define MAXMISS		10
-
-
-
-/* special status to close upvalues preserving the top of the stack */
-#define CLOSEKTOP	(-1)
+#define sizeLclosure(n)	(cast(int, sizeof(LClosure)) + \
+                         cast(int, sizeof(TValue *)*((n)-1)))
 
 
 LUAI_FUNC Proto *luaF_newproto (lua_State *L);
-LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nupvals);
-LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nupvals);
-LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
+LUAI_FUNC Closure *luaF_newCclosure (lua_State *L, int nelems);
+LUAI_FUNC Closure *luaF_newLclosure (lua_State *L, int nelems);
+LUAI_FUNC UpVal *luaF_newupval (lua_State *L);
 LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
-LUAI_FUNC void luaF_newtbcupval (lua_State *L, StkId level);
-LUAI_FUNC void luaF_closeupval (lua_State *L, StkId level);
-LUAI_FUNC StkId luaF_close (lua_State *L, StkId level, int status, int yy);
-LUAI_FUNC void luaF_unlinkupval (UpVal *uv);
+LUAI_FUNC void luaF_close (lua_State *L, StkId level);
 LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
+LUAI_FUNC void luaF_freeupval (lua_State *L, UpVal *uv);
 LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
                                          int pc);