[llvm] [GISel] Introduce MachineIRBuilder::(build|materialize)ObjectPtrOffset (PR #150392)

[Fabian Ritter via llvm-commits]

ritter-x2a wrote:

### Merge activity

* **Jul 29, 9:12 AM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/150392).


https://github.com/llvm/llvm-project/pull/150392