[llvm] [VectorCombine] Fix rotation in phi narrowing. (PR #160465)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `llvm` at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/40716

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

```
Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
...
PASS: Flang :: Semantics/synchronization01b.f90 (3837 of 3847)
PASS: Flang :: Semantics/synchronization03a.f90 (3838 of 3847)
PASS: Flang :: Semantics/structconst05.f90 (3839 of 3847)
PASS: Flang :: Semantics/modfile71.F90 (3840 of 3847)
PASS: Flang :: Transforms/debug-dwarf-version.fir (3841 of 3847)
PASS: Flang :: Transforms/debug-line-table.fir (3842 of 3847)
PASS: Flang :: Transforms/debug-omp-target-op-1.fir (3843 of 3847)
PASS: Flang :: Semantics/mod-file-rewriter.f90 (3844 of 3847)
PASS: Flang :: Driver/omp-driver-offload.f90 (3845 of 3847)
PASS: Flang :: Intrinsics/math-codegen.fir (3846 of 3847)
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2179.619939

```

</details>

https://github.com/llvm/llvm-project/pull/160465