[llvm] Fold patterns which uses <2N x iM> type for comparisons on <N x i2M> type (PR #184328)

[Simon Pilgrim via llvm-commits]

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@@ -467,6 +484,10 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
     return Sel;
   }
 
+  Instruction *foldVni2mCmpEqUsingV2nim(Instruction &I);
+
+  Instruction *foldVni2mCmpGtUsingV2nim(Instruction &I);
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RKSimon wrote:

just provide a single wrapper function (since most cases call both anyhow)? Put it with all the other visit/fold/canonicalize declarations earlier in the class.

a better (brief but descriptive) name would be nice as well

https://github.com/llvm/llvm-project/pull/184328