[llvm] LTO: Stop overwriting the merged module's DataLayout (PR #223987)

[Alexis Engelke via llvm-commits]

https://github.com/aengelke approved this pull request.

LGTM.

> That seems like creating an obstacle to heterogenous modules

I'm not very familiar with that area. Why do such modules have to be in the same context? Is there a place to read up on that?

https://github.com/llvm/llvm-project/pull/223987