[llvm] [DebugInfo][RemoveDIs] Have getInsertionPtAfterDef return an iterator (PR #73149)

[Jeremy Morse via llvm-commits]

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@@ -643,8 +655,10 @@ Value *GuardWideningImpl::freezeAndPush(Value *Orig, Instruction *InsertPt) {
     if (Visited.insert(Def).second) {
       if (isGuaranteedNotToBePoison(Def, nullptr, InsertPt, &DT))
         return true;
-      CacheOfFreezes[Def] = new FreezeInst(Def, Def->getName() + ".gw.fr",
-                                           getFreezeInsertPt(Def, DT));
+      BasicBlock::iterator InsertPt = *getFreezeInsertPt(Def, DT);
+      FreezeInst *FI = new FreezeInst(Def, Def->getName() + ".gw.fr");
+      FI->insertBefore(*InsertPt->getParent(), InsertPt);
+      CacheOfFreezes[Def] = FI;
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jmorse wrote:

We can certainly restore this back to "insert in the constructor", I'm just shying away from landing that right now. IMO it's better to land as one-foul-swoop which breaks downstream builds, but only does it once.

https://github.com/llvm/llvm-project/pull/73149