[llvm] Fixes [AArch64] Assertion `EltCnt.isKnownEven() && "Cannot halve vector with odd number of elements."' failed. (PR #166528)

[Benjamin Maxwell via llvm-commits]

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+; RUN: opt -mtriple=aarch64-unknown-linux-gnu -mattr=+sve -passes=vector-combine %s -S -o - | FileCheck %s
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MacDue wrote:

The crash reported in https://github.com/llvm/llvm-project/issues/166320 only occurs if the instcombine is run without `+sve`. So if you want to test that you've fixed that crash, the test should not have `+sve`. 

https://github.com/llvm/llvm-project/pull/166528