[llvm] [CodeGenPrepare][NFC] Reland: Update the dominator tree instead of rebuilding it (PR #179040)

[Mingjie Xu via llvm-commits]

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@@ -312,6 +322,8 @@ class CodeGenPrepare {
   const TargetTransformInfo *TTI = nullptr;
   const BasicBlockSectionsProfileReader *BBSectionsProfileReader = nullptr;
   const TargetLibraryInfo *TLInfo = nullptr;
+  DominatorTree *DT = nullptr;
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Enna1 wrote:

Thanks, done.

https://github.com/llvm/llvm-project/pull/179040