[llvm] [LoopVectorizer] Prune VFs based on plan register pressure (PR #132190)

[Sander de Smalen via llvm-commits]

================
@@ -4188,28 +4191,8 @@ ElementCount LoopVectorizationCostModel::getMaximizedVFForTarget(
         llvm::bit_floor(WidestRegister.getKnownMinValue() / SmallestType),
         ComputeScalableMaxVF);
     MaxVectorElementCountMaxBW = MinVF(MaxVectorElementCountMaxBW, MaxSafeVF);
+    MaxVF = MaxVectorElementCountMaxBW;
----------------
sdesmalen-arm wrote:

nit:
```suggestion
    MaxVF = MinVF(MaxVectorElementCountMaxBW, MaxSafeVF);
```
(MaxVectorElementCountMaxBW is not used after this point)

https://github.com/llvm/llvm-project/pull/132190