[llvm] fix a bug of PPCMIPeepholes which description in issue 71030 (PR #85451)

[Amy Kwan via llvm-commits]

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@@ -0,0 +1,702 @@
+# RUN: llc -run-pass=ppc-mi-peepholes  -mtriple powerpc64-ibm-aix-xcoff %s -o - \
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amy-kwan wrote:

Could we commit this test case first before this patch? Then, it will be easier to see how this patch changes the test case.

https://github.com/llvm/llvm-project/pull/85451