[llvm] [VPlan] Separate out logic to manage IR flags to VPIRFlags (NFC). (PR #140621)

[via llvm-commits]

================
@@ -151,14 +151,14 @@ void UnrollState::unrollWidenInductionByUF(
       IV->getParent()->getEnclosingLoopRegion()->getSinglePredecessor());
   Type *IVTy = TypeInfo.inferScalarType(IV);
   auto &ID = IV->getInductionDescriptor();
-  std::optional<FastMathFlags> FMFs;
+  VPIRFlags Flags;
   if (isa_and_present<FPMathOperator>(ID.getInductionBinOp()))
-    FMFs = ID.getInductionBinOp()->getFastMathFlags();
+    Flags = ID.getInductionBinOp()->getFastMathFlags();
----------------
ayalz wrote:

consistency nit: {} are used above in `Flags = {VPI->getFastMathFlags()};`?

https://github.com/llvm/llvm-project/pull/140621