feat: 适配 Lua 5.5.1 最新版 (lua_5.5.1 分支)

- lib/lua 替换为 Lua 5.5.1 官方源码(2026-07 发布, 当前最新)
- luaconf.h LUA_EXTRASPACE 扩为 272 字节(与 5.4.8 同方案)
- C API 完全兼容, 桥接层零改动
- PackagePathConfig 测试沿用跨版本语义断言(5.4+ require 返回 loader data 路径)
- 验证: GTest 44/44 通过

lib/lua/lmem.h

@@ -39,11 +39,11 @@
 ** 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'.)
+** '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))))
+     cast_int((MAX_SIZET/sizeof(t))))
 
 
 /*
@@ -57,12 +57,15 @@
 #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_newvector(L,n,t)  \
+	cast(t*, luaM_malloc_(L, cast_sizet(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_newblock(L, size)	luaM_newvector(L, size, char)
+
 #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)))
@@ -83,10 +86,10 @@ 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,
+                               int *size, unsigned 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);
+                                    int final_n, unsigned size_elem);
 LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag);
 
 #endif