[MLIR-HLO] Missing legalization for mhlo.scatter to standard MLIR
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 ### Issue Type

Support

### Have you reproduced the bug with TF nightly?

No

### Source

source

### Tensorflow Version

main branch

### Custom Code

Yes

### OS Platform and Distribution

_No response_

### Mobile device

_No response_

### Python version

_No response_

### Bazel version

_No response_

### GCC/Compiler version

_No response_

### CUDA/cuDNN version

_No response_

### GPU model and memory

_No response_

### Current Behaviour?

See below.

### Standalone code to reproduce the issue

```shell
mhlo.scatter
```


### Relevant log output

_No response_</details>

### Problem Statement

Is there a pass (sequence) that can lower the `mhlo.scatter` operation to standard MLIR dialects, such as linalg, tensor, arith, and/or scf?

The goal is to ultimately lower to the LLVM dialect and perform codegen with LLVM. I wasn't able to find a pass that converts the `mhlo.scatter` op out of the MLIR-HLO dialect domain. Most other ops can be converter via passes like `--hlo-legalize-to-linalg`, `--mhlo-legalize-to-std`, or `--mhlo-legalize-control-flow`. 

(Duplicate of https://github.com/tensorflow/mlir-hlo/issues/64 since I'm not sure that repository is monitored for issues.)