[llvm] LiveIntervals: Use BumpPtrAllocator (PR #127057)

[Jay Foad via llvm-commits]

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@@ -64,6 +65,8 @@ class LiveIntervals {
   MachineDominatorTree *DomTree = nullptr;
   std::unique_ptr<LiveIntervalCalc> LICalc;
 
+  BumpPtrAllocator Allocator;
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jayfoad wrote:

Comment saying what this is used for?

https://github.com/llvm/llvm-project/pull/127057