[llvm] [RemoveDIs] Fix SimplifyCFG behaviour to match existing behaviour (PR #82981)

[Jeremy Morse via llvm-commits]

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@@ -3208,8 +3208,8 @@ bool SimplifyCFGOpt::SpeculativelyExecuteBB(BranchInst *BI,
   // end of this block.
   for (auto &It : make_range(ThenBB->begin(), ThenBB->end()))
     for (DbgRecord &DR : make_early_inc_range(It.getDbgValueRange()))
-      if (DPValue *DPV = dyn_cast<DPValue>(&DR); DPV && !DPV->isDbgAssign())
-        It.dropOneDbgValue(DPV);
+      if (DPValue *DPV = dyn_cast<DPValue>(&DR); !DPV || !DPV->isDbgAssign())
+        It.dropOneDbgValue(&DR);
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jmorse wrote:

Is this condition going to become `!isa<DbgAssign>` in the future-class-refactor? It's worth commenting on what you're filtering for seeing how the current arrangement makes it non-obvious.

https://github.com/llvm/llvm-project/pull/82981