[llvm] [LV] Nest cl::opts under namespace llvm (NFC) (PR #221891)

[Ramkumar Ramachandra via llvm-commits]

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@@ -51,6 +51,9 @@
 
 namespace llvm {
 
+LLVM_ABI extern cl::opt<unsigned> NumberOfStoresToPredicate;
+LLVM_ABI extern cl::opt<bool> VPlanBuildOuterloopStressTest;
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artagnon wrote:

Yes, alright: there's ForceTargetInstructionCost, which I think I added to LoopVectorizationPlanner.h in https://github.com/llvm/llvm-project/pull/130601, with the same rationale.

https://github.com/llvm/llvm-project/pull/221891