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

[Fabian Ritter via llvm-commits]

ritter-x2a wrote:

This PR caused a buildbot failure for M68k: https://lab.llvm.org/buildbot/#/builders/27/builds/13793
I'll have a PR to fix the failing tests ready in a couple of minutes.

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