[llvm] [LoopVectorize] Add metadata to distinguish vectorized loop body from scalar remainder (PR #190258)

[Florian Hahn via llvm-commits]

================
@@ -0,0 +1,110 @@
+; RUN: opt < %s -S -passes='loop-vectorize,loop-unroll' \
----------------
fhahn wrote:

Would be good to have the emission of the metadata checked in a test in `llvm/test/Transforms/LoopVectorize`

https://github.com/llvm/llvm-project/pull/190258