Revert "[ControlHeightReduction] Drop lifetime annotations where necessary (#159686)"

This reverts commit a004509.

Looks like this one is actually breaking the buildbots. Reverting the switch back
to IRPGO did not fix things.

Author: boomanaiden154

llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp

@@ -1591,31 +1591,14 @@ static void insertTrivialPHIs(CHRScope *Scope,
         }
         TrivialPHIs.insert(PN);
         CHR_DEBUG(dbgs() << "Insert phi " << *PN << "\n");
-        bool FoundLifetimeAnnotation = false;
         for (Instruction *UI : Users) {
-          // If we found a lifetime annotation, remove it, but set a flag
-          // to ensure that we remove all other lifetime annotations attached
-          // to the alloca.
-          if (UI->isLifetimeStartOrEnd()) {
-            UI->eraseFromParent();
-            FoundLifetimeAnnotation = true;
-            continue;
-          }
           for (unsigned J = 0, NumOps = UI->getNumOperands(); J < NumOps; ++J) {
             if (UI->getOperand(J) == &I) {
               UI->setOperand(J, PN);
             }
           }
           CHR_DEBUG(dbgs() << "Updated user " << *UI << "\n");
         }
-        // Erase any leftover lifetime annotations for a dynamic alloca.
-        if (FoundLifetimeAnnotation) {
-          for (User *U : make_early_inc_range(I.users())) {
-            if (auto *UI = dyn_cast<Instruction>(U))
-              if (UI->isLifetimeStartOrEnd())
-                UI->eraseFromParent();
-          }
-        }
       }
     }
   }
@@ -1710,12 +1693,14 @@ void CHR::transformScopes(CHRScope *Scope, DenseSet<PHINode *> &TrivialPHIs) {
   BasicBlock *ExitBlock = LastRegion->getExit();
   std::optional<uint64_t> ProfileCount = BFI.getBlockProfileCount(EntryBlock);
 
-  SmallVector<AllocaInst *> StaticAllocas;
-  for (Instruction &I : *EntryBlock) {
-    if (auto *AI = dyn_cast<AllocaInst>(&I)) {
-      if (AI->isStaticAlloca())
-        StaticAllocas.push_back(AI);
-    }
+  if (ExitBlock) {
+    // Insert a trivial phi at the exit block (where the CHR hot path and the
+    // cold path merges) for a value that's defined in the scope but used
+    // outside it (meaning it's alive at the exit block). We will add the
+    // incoming values for the CHR cold paths to it below. Without this, we'd
+    // miss updating phi's for such values unless there happens to already be a
+    // phi for that value there.
+    insertTrivialPHIs(Scope, EntryBlock, ExitBlock, TrivialPHIs);
   }
 
   // Split the entry block of the first region. The new block becomes the new
@@ -1734,20 +1719,6 @@ void CHR::transformScopes(CHRScope *Scope, DenseSet<PHINode *> &TrivialPHIs) {
   FirstRegion->replaceEntryRecursive(NewEntryBlock);
   BasicBlock *PreEntryBlock = EntryBlock;
 
-  // Move static allocas into the pre-entry block so they stay static.
-  for (AllocaInst *AI : StaticAllocas)
-    AI->moveBefore(EntryBlock->getTerminator()->getIterator());
-
-  if (ExitBlock) {
-    // Insert a trivial phi at the exit block (where the CHR hot path and the
-    // cold path merges) for a value that's defined in the scope but used
-    // outside it (meaning it's alive at the exit block). We will add the
-    // incoming values for the CHR cold paths to it below. Without this, we'd
-    // miss updating phi's for such values unless there happens to already be a
-    // phi for that value there.
-    insertTrivialPHIs(Scope, EntryBlock, ExitBlock, TrivialPHIs);
-  }
-
   ValueToValueMapTy VMap;
   // Clone the blocks in the scope (excluding the PreEntryBlock) to split into a
   // hot path (originals) and a cold path (clones) and update the PHIs at the