[llvm] [AArch64][SME] Introduce CHECK_MATCHING_VL pseudo for streaming transitions (PR #157510)

[Benjamin Maxwell via llvm-commits]

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+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
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MacDue wrote:

It may be nice to have a test that shows, for a few (not as many as this), what the Machine IR looks like before/after expansion. This would need to be another file that uses `update_mir_test_checks.py` with two run lines, one with `-stop-before=finalize-isel` and one with `-stop-after=finalize-isel` (similar to the `llvm/test/CodeGen/AArch64/aarch64-sme-za-call-lowering.ll` test).



https://github.com/llvm/llvm-project/pull/157510