[llvm] [VectorCombine] Fold bitcast(bitreverse.v8i8(bitcast(IntTy))) into bswap+bitreverse (PR #209037)

[Simon Pilgrim via llvm-commits]

================
@@ -0,0 +1,60 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes=vector-combine -mtriple=aarch64 < %s | FileCheck %s
----------------
RKSimon wrote:

always good to add big-endian test coverage as well if you can to anything involving bswap/bitrev

https://github.com/llvm/llvm-project/pull/209037