[llvm] [LV] Remove DataAndControlFlowWithoutRuntimeCheck. NFC (PR #183762)

[Luke Lau via llvm-commits]

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@@ -1608,8 +1596,7 @@ class LoopVectorizationCostModel {
 
   /// Control finally chosen tail folding style. The first element is used if
   /// the IV update may overflow, the second element - if it does not.
-  std::optional<std::pair<TailFoldingStyle, TailFoldingStyle>>
-      ChosenTailFoldingStyle;
+  std::optional<TailFoldingStyle> ChosenTailFoldingStyle;
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lukel97 wrote:

setTailFoldingStyle checks it's unset to make sure it's only set once, but looking through the git blame it looks like it didn't used to be an std::optional before the EVL stuff was added, it just checked it was TailFoldingStyle::None. 

Removed the optional in d13671bd4c83, good idea thanks! The type's much simpler now

https://github.com/llvm/llvm-project/pull/183762