[llvm] [VectorCombine] Fix scalarizeExtExtract for big-endian (PR #157962)

[Simon Pilgrim via llvm-commits]

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+; RUN: opt -passes='vector-combine,dce' -S -mtriple=aarch64-unknown-linux-gnu %s -o - | FileCheck %s --check-prefix=LE
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RKSimon wrote:

You can create a PowerPC subdir if you want to retain the powerpc64 triple test coverage - but you will need to duplicate the file

https://github.com/llvm/llvm-project/pull/157962