[llvm] LoopVectorize: add test for crash in #72969 (PR #74111)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,26 @@
+; RUN: not --crash opt -passes=loop-vectorize -S < %s
+
+target triple = "x86_64-unknown-linux-gnu"
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fhahn wrote:

If this depends on the X86 backend, it needs to go in the `X86` subdirectory so it only runs when the X86 backend is built. Can it be made target-independent by using `-force-vector-width`/`-force-vector-interleave`?

https://github.com/llvm/llvm-project/pull/74111