Declaration order dependent checker error

[FrancisTheCat]

Context

Operating System & Odin Version:

Odin:    dev-2025-11:5e3648b83
OS:      Arch Linux, Linux 6.17.8-arch1-1
CPU:     AMD Ryzen 5 7640U w/ Radeon 760M Graphics
RAM:     19798 MiB
Backend: LLVM 21.1.5

Current Behavior

This is fine:

package test

Foo :: union { Bar, }
Bar :: union { ^Foo, }

This errors, but should not:

package test

Bar :: union { ^Foo, }
Foo :: union { Bar, }

test.odin(4:16) Error: Invalid variant type in union 'Bar'
	Foo :: union { Bar, }
	               ^~^