[llvm] [Instcombine] Fix crash in foldMinimumMaximumSharedOp. (PR #173705)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-mlir-rhel-clang` running on `ppc64le-mlir-rhel-test` while building `llvm` at step 3 "clean-build-dir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/36161

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 3 (clean-build-dir) failure: Delete failed. (failure) (timed out)
Step 6 (test-build-check-mlir-build-only-check-mlir) failure: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
...
PASS: MLIR-Unit :: Analysis/Presburger/./MLIRPresburgerTests/79/177 (3782 of 3799)
PASS: MLIR :: Conversion/SCFToOpenMP/scf-to-openmp.mlir (3783 of 3799)
PASS: MLIR :: CAPI/irdl.c (3784 of 3799)
PASS: MLIR-Unit :: Analysis/Presburger/./MLIRPresburgerTests/8/177 (3785 of 3799)
PASS: MLIR :: Dialect/GPU/all-reduce-add.mlir (3786 of 3799)
PASS: MLIR :: Dialect/Bufferization/Transforms/one-shot-module-bufferize-force-copy-before-write.mlir (3787 of 3799)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/11/22 (3788 of 3799)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/12/22 (3789 of 3799)
PASS: MLIR-Unit :: IR/./MLIRIRTests/101/131 (3790 of 3799)
PASS: MLIR-Unit :: IR/./MLIRIRTests/100/131 (3791 of 3799)
command timed out: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2470.372924

```

</details>

https://github.com/llvm/llvm-project/pull/173705