[llvm] DAG: Fix latent verifier error in statepoint lowering (PR #222894)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata commented:

IIUC, you are fixing a wrong-code bug. The verifier is just a messenger here. How about a title like this?

`DAG: Fix cross-block gc.relocate of constants and allocas`

https://github.com/llvm/llvm-project/pull/222894