[llvm] Patch 1: [LV][NFCI] Parameterize CM instance for the Planner (PR #202818)

[Hassnaa Hamdi via llvm-commits]

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@@ -803,9 +803,6 @@ class LoopVectorizationPlanner {
   /// The legality analysis.
   LoopVectorizationLegality *Legal;
 
-  /// The profitability analysis.
-  LoopVectorizationCostModel &CM;
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hassnaaHamdi wrote:

Sometimes I need both instances at same time, for example at functions: `plan(..)` and `computeBestVF` because some of the logic of those functions should be run for the default CM and some other logic is for the second CM.
For example in `plan(..)`, if the user is specifying VF, we use the `UserVf` for the first CM and we use the `EpilogueUserVF` for the second CM, so we need both instances.

https://github.com/llvm/llvm-project/pull/202818