[llvm] [AMDGPU][SDAG] Initial support for ISD::PTRADD (PR #141725)

[Fabian Ritter via llvm-commits]

ritter-x2a wrote:

### Merge activity

* **Jun 13, 1:59 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/141725).


https://github.com/llvm/llvm-project/pull/141725