fix(gen): 函数指针变量别名（f2: rawptr = f）继承已注册的返回类型签名，修 rawptr 间接调用的签名缺失 fail-fast

App/lib/core/Gen/AssignGenMixin.vp

@@ -2129,6 +2129,16 @@ novirtual class AssignGenMixin:
         if callable_ret is not None:
             # Nonzero return already reported inside register_func_ptr_sig; this branch is defensive
             if self.Gen.CallGenLeafKit.register_func_ptr_sig(pool, nm.id, callable_ret, aa) != 0: return 0
+        elif aa.value is not None and aa.value.kind() == ast.ASTKind.Name:
+            # Function-pointer alias: `f2: rawptr = f` inherits f's already-registered return
+            # type, so a later indirect call `f2()` can rebuild the callee type. The `rawptr`
+            # annotation carries no callable information of its own, and without this the indirect
+            # call would fail fast (see _translate_func_ptr_call's "not registered" error).
+            src_nm: ast.Name* = ast.Name*(aa.value)
+            if src_nm.id is not None:
+                src_ret: mlirlite.LLVMType* = self.Gen.CallGenLeafKit.lookup_func_ptr_ret(src_nm.id)
+                if src_ret is not None:
+                    if self.Gen.CallGenLeafKit.register_func_ptr_sig(pool, nm.id, src_ret, aa) != 0: return 0
 
         # Value-position volatile call prefix: mark the result slot volatile
         if aa.value is not None and aa.value.kind() == ast.ASTKind.Call and (ast.Call*(aa.value)).IsVolatile != 0 and nm.id is not None: