[llvm] [DebugInfo][SimpleLoopUnswitch] Fix missing debug location updates for new terminators (PR #98789)

[Stephen Tozer via llvm-commits]

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@@ -667,9 +668,11 @@ static bool unswitchTrivialBranch(Loop &L, BranchInst &BI, DominatorTree &DT,
   if (FullUnswitch) {
     if (MSSAU) {
       // Remove the cloned branch instruction.
-      ParentBB->getTerminator()->eraseFromParent();
+      Instruction *Term = ParentBB->getTerminator();
+      Term->eraseFromParent();
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SLTozer wrote:

I believe `eraseFromParent` frees the instruction, so we should copy the DebugLoc (either to the new instruction or as a local variable) before erasing it.

https://github.com/llvm/llvm-project/pull/98789