[llvm] [DirectX] Remove lifetime intrinsics and run Dead Store Elimination (PR #152636)

[Farzon Lotfi via llvm-commits]

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@@ -78,6 +82,17 @@ static bool forwardHandleAccesses(Function &F, DominatorTree &DT) {
         case Intrinsic::dx_resource_handlefromimplicitbinding:
           processHandle(II, HandleMap);
           break;
+        // Note: Lifetime intrinsics do not show up as users of an Alloca.
+        // As a result we walk the whole function to find the lifetimes and
+        // store them so that we may delete the alloca matches
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farzonl wrote:

I did it this way because the uses by lifetime intrinsics weren’t showing up when i was trying in the loop on 124.

https://github.com/llvm/llvm-project/pull/152636