fix(gen): define 复用前置声明时按源码形参名对齐签名参数名，修签名与函数体两套参数名导致 MLIR「region entry argument already in use」

App/lib/core/Gen/Func/FuncGenDef.vp

@@ -462,6 +462,33 @@ novirtual class FuncGenDef(CallGenBase.CallGenBase):
         if func is not None and mlirlite.function_is_declared(func) != 0:
             # Reuse the forward declare: clear IsDeclared and turn it into a define
             func.IsDeclared = 0
+            # 参数名对齐（根因修复）：复用的前置声明未必是 forward_declare_functions 按源码建的，也可能是
+            # **模块前言**里 Translator 建的 C 库声明（如 free 用合成名 "p"）。而函数体是用**源码形参名**
+            # %<arg.arg> 生成参数 SSA 引用的（见下方 alloca 段的 SSAValue）。若签名沿用声明里的旧名，就会
+            # 打印出 `llvm.func @f(%p) { ... %ptr ... }`：入口实参是 %p，体内 %ptr 却在 f 内未定义，
+            # mlir-opt 会把 %ptr 解析到后续同名函数的入口实参并报 "region entry argument '%ptr' is already
+            # in use"（现场：VKernel 的 free 头 %p / 体 %ptr，被解析到 _slab_find_page(%ptr)）。
+            # 故这里按源码形参名重写复用到的形参名，使签名与函数体一致。forward_declare_functions 建的前置
+            # 声明本就用源码名，此处对其幂等（同名重写）。
+            reused_p: mlirlite.Param* = mlirlite.function_get_param_head(func)
+            if args_node is not None:
+                reuse_ags: ast.Arguments* = ast.Arguments*(args_node)
+                if reuse_ags.args is not None:
+                    reuse_list: list[ast.AST*]* = reuse_ags.args
+                    reuse_n: sizet = len(reuse_list)
+                    for reuse_i in range(int(reuse_n)):
+                        rearg: ast.Arg* = ast.Arg*(reuse_list.get(reuse_i))
+                        if rearg is None or rearg.arg is None: continue
+                        # CVoid means empty param: not part of the signature (mirrors the add_param loops above)
+                        if rearg.annotation is not None and self.Gen.TypeGenResolve._is_t_attr(rearg.annotation, "CVoid", imported_modules) != 0: continue
+                        if reused_p is None:
+                            # 复用声明形参少于定义：签名与函数体必然错配，禁止静默，fail-fast
+                            self.Gen.TypeGenErr.fatal_error(rearg, f"reused declaration for '{fd.name}' has fewer parameters than the definition", "TypeError")
+                            return 0
+                        reuse_pname: str = pool.alloc(32)
+                        if reuse_pname is not None: viperlib.snprintf(reuse_pname, 32, "%%%s", rearg.arg)
+                        reused_p.Name = reuse_pname
+                        reused_p = mlirlite.param_get_next(reused_p)
             # Set decorator attributes (not set when the forward declare was created)
             func_attrs_reuse: str = self.Gen.FuncGenBase.extract_func_attrs(pool, fd.decorator_list, imported_modules)
             if func_attrs_reuse is not None: mlirlite.function_set_attrs(func, func_attrs_reuse)