`#all_or_none` Not Working With `using`

[dozn]

package main

import "core:fmt"

S :: struct #all_or_none { a, b: int }
S2 :: struct { using _: S }

main :: proc() {
	s := S2{a = 5}
	fmt.printfln("%#v", s)
}

Expected

Same error as replacing it with s := S2{S{a = 5}} instead:
Error: All or none of the fields must be assigned to a struct with '#all_or_none' applied, missing fields: ...

Actual

Compiles successfully.

---

Odin: dev-2025-11:56aab55d8
OS: Windows 11 Professional (version: 25H2), build 26200.7171
CPU: AMD Ryzen 7 7700 8-Core Processor
RAM: 61033 MiB
Backend: LLVM 20.1.0