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/lmem.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h $
+** $Id: lmem.h,v 1.40.1.1 2013/04/12 18:48:47 roberto Exp $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -14,80 +14,44 @@
 #include "lua.h"
 
 
-#define luaM_error(L)	luaD_throw(L, LUA_ERRMEM)
-
-
 /*
-** This macro tests whether it is safe to multiply 'n' by the size of
-** type 't' without overflows. Because 'e' is always constant, it avoids
-** the runtime division MAX_SIZET/(e).
-** (The macro is somewhat complex to avoid warnings:  The 'sizeof'
-** comparison avoids a runtime comparison when overflow cannot occur.
-** The compiler should be able to optimize the real test by itself, but
-** when it does it, it may give a warning about "comparison is always
-** false due to limited range of data type"; the +1 tricks the compiler,
-** avoiding this warning but also this optimization.)
+** This macro avoids the runtime division MAX_SIZET/(e), as 'e' is
+** always constant.
+** The macro is somewhat complex to avoid warnings:
+** +1 avoids warnings of "comparison has constant result";
+** cast to 'void' avoids warnings of "value unused".
 */
-#define luaM_testsize(n,e)  \
-	(sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e))
+#define luaM_reallocv(L,b,on,n,e) \
+  (cast(void, \
+     (cast(size_t, (n)+1) > MAX_SIZET/(e)) ? (luaM_toobig(L), 0) : 0), \
+   luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
 
-#define luaM_checksize(L,n,e)  \
-	(luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0))
+#define luaM_freemem(L, b, s)	luaM_realloc_(L, (b), (s), 0)
+#define luaM_free(L, b)		luaM_realloc_(L, (b), sizeof(*(b)), 0)
+#define luaM_freearray(L, b, n)   luaM_reallocv(L, (b), n, 0, sizeof((b)[0]))
 
+#define luaM_malloc(L,s)	luaM_realloc_(L, NULL, 0, (s))
+#define luaM_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t)))
+#define luaM_newvector(L,n,t) \
+		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
 
-/*
-** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that
-** the result is not larger than 'n' and cannot overflow a 'size_t'
-** when multiplied by the size of type 't'. (Assumes that 'n' is an
-** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.)
-*/
-#define luaM_limitN(n,t)  \
-  ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) :  \
-     cast_uint((MAX_SIZET/sizeof(t))))
-
-
-/*
-** Arrays of chars do not need any test
-*/
-#define luaM_reallocvchar(L,b,on,n)  \
-  cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
-
-#define luaM_freemem(L, b, s)	luaM_free_(L, (b), (s))
-#define luaM_free(L, b)		luaM_free_(L, (b), sizeof(*(b)))
-#define luaM_freearray(L, b, n)   luaM_free_(L, (b), (n)*sizeof(*(b)))
-
-#define luaM_new(L,t)		cast(t*, luaM_malloc_(L, sizeof(t), 0))
-#define luaM_newvector(L,n,t)	cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0))
-#define luaM_newvectorchecked(L,n,t) \
-  (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t))
-
-#define luaM_newobject(L,tag,s)	luaM_malloc_(L, (s), tag)
+#define luaM_newobject(L,tag,s)	luaM_realloc_(L, NULL, tag, (s))
 
 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
-	((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \
-                         luaM_limitN(limit,t),e)))
+          if ((nelems)+1 > (size)) \
+            ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
 
 #define luaM_reallocvector(L, v,oldn,n,t) \
-   (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \
-                                  cast_sizet(n) * sizeof(t))))
-
-#define luaM_shrinkvector(L,v,size,fs,t) \
-   ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t))))
+   ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
 
 LUAI_FUNC l_noret luaM_toobig (lua_State *L);
 
 /* not to be called directly */
 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
                                                           size_t size);
-LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize,
-                                                              size_t size);
-LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize);
-LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems,
-                               int *size, int size_elem, int limit,
+LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
+                               size_t size_elem, int limit,
                                const char *what);
-LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem,
-                                    int final_n, int size_elem);
-LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag);
 
 #endif