[llvm] [Peephole] Check instructions from CopyMIs are still COPY (PR #69511)

[via llvm-commits]

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@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 3
+; RUN: llc < %s -mtriple=i686-- | FileCheck %s
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qcolombet wrote:

Could you make this only a peephole test using `.mir`?

The description mentions a `COPY` but from the IR it is unclear where it comes from and what happens to it in the peephole optimizer.

https://github.com/llvm/llvm-project/pull/69511