[llvm] [SandboxVectorizer] New class to actually collect and manage seeds (PR #112979)

[via llvm-commits]

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@@ -60,6 +60,16 @@ class Utils {
         getUnderlyingObject(LSI->getPointerOperand()->Val));
   }
 
+  /// \Returns the number of elements in \p Ty, that is the number of lanes
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vporpo wrote:

I am actually using this exact function in one of the Legality patches and I placed it in `VecUtils.h`, but it's up to you if you want to create the file now or later, either way is fine with me. If you decide to keep it in `Utils.h` please add a TODO so that we remember to clean it up later.

https://github.com/llvm/llvm-project/pull/112979