[llvm] [MachinePipeliner] Fix fragile tests (PR #123169)

[Ryotaro Kasuga via llvm-commits]

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@@ -0,0 +1,267 @@
+# RUN: llc -mtriple=hexagon -mcpu=hexagonv73 -O2 -mattr=+hvxv73,hvx-length64b \
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kasuga-fj wrote:

I didn't explain myself well enough. It seems to me that the original test checks the behavior of the `hexagon-loop-align` pass, which runs after the pipeliner. The mir code of this case is generated by the command like the following:

```
llc loop_align_count.ll --stop-before=hexagon-loop-align ...
```

This means that the pipeliner is already applied.  I believe the original test doesn't assume to verify the pipeliner, and if so, I think this change makes sense. However, I'm not sure if it causes any problem if the pipeliner's scheduling result has changed for the original IR.

https://github.com/llvm/llvm-project/pull/123169