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diff --git a/contrib/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/contrib/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
deleted file mode 100644
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--- a/contrib/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
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@@ -1,267 +0,0 @@
-//===- LoopDeletion.cpp - Dead Loop Deletion Pass ---------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the Dead Loop Deletion Pass. This pass is responsible
-// for eliminating loops with non-infinite computable trip counts that have no
-// side effects or volatile instructions, and do not contribute to the
-// computation of the function's return value.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Scalar/LoopDeletion.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/GlobalsModRef.h"
-#include "llvm/Analysis/LoopPass.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/PatternMatch.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Scalar/LoopPassManager.h"
-#include "llvm/Transforms/Utils/LoopUtils.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "loop-delete"
-
-STATISTIC(NumDeleted, "Number of loops deleted");
-
-enum class LoopDeletionResult {
-  Unmodified,
-  Modified,
-  Deleted,
-};
-
-/// Determines if a loop is dead.
-///
-/// This assumes that we've already checked for unique exit and exiting blocks,
-/// and that the code is in LCSSA form.
-static bool isLoopDead(Loop *L, ScalarEvolution &SE,
-                       SmallVectorImpl<BasicBlock *> &ExitingBlocks,
-                       BasicBlock *ExitBlock, bool &Changed,
-                       BasicBlock *Preheader) {
-  // Make sure that all PHI entries coming from the loop are loop invariant.
-  // Because the code is in LCSSA form, any values used outside of the loop
-  // must pass through a PHI in the exit block, meaning that this check is
-  // sufficient to guarantee that no loop-variant values are used outside
-  // of the loop.
-  bool AllEntriesInvariant = true;
-  bool AllOutgoingValuesSame = true;
-  for (PHINode &P : ExitBlock->phis()) {
-    Value *incoming = P.getIncomingValueForBlock(ExitingBlocks[0]);
-
-    // Make sure all exiting blocks produce the same incoming value for the exit
-    // block.  If there are different incoming values for different exiting
-    // blocks, then it is impossible to statically determine which value should
-    // be used.
-    AllOutgoingValuesSame =
-        all_of(makeArrayRef(ExitingBlocks).slice(1), [&](BasicBlock *BB) {
-          return incoming == P.getIncomingValueForBlock(BB);
-        });
-
-    if (!AllOutgoingValuesSame)
-      break;
-
-    if (Instruction *I = dyn_cast<Instruction>(incoming))
-      if (!L->makeLoopInvariant(I, Changed, Preheader->getTerminator())) {
-        AllEntriesInvariant = false;
-        break;
-      }
-  }
-
-  if (Changed)
-    SE.forgetLoopDispositions(L);
-
-  if (!AllEntriesInvariant || !AllOutgoingValuesSame)
-    return false;
-
-  // Make sure that no instructions in the block have potential side-effects.
-  // This includes instructions that could write to memory, and loads that are
-  // marked volatile.
-  for (auto &I : L->blocks())
-    if (any_of(*I, [](Instruction &I) { return I.mayHaveSideEffects(); }))
-      return false;
-  return true;
-}
-
-/// This function returns true if there is no viable path from the
-/// entry block to the header of \p L. Right now, it only does
-/// a local search to save compile time.
-static bool isLoopNeverExecuted(Loop *L) {
-  using namespace PatternMatch;
-
-  auto *Preheader = L->getLoopPreheader();
-  // TODO: We can relax this constraint, since we just need a loop
-  // predecessor.
-  assert(Preheader && "Needs preheader!");
-
-  if (Preheader == &Preheader->getParent()->getEntryBlock())
-    return false;
-  // All predecessors of the preheader should have a constant conditional
-  // branch, with the loop's preheader as not-taken.
-  for (auto *Pred: predecessors(Preheader)) {
-    BasicBlock *Taken, *NotTaken;
-    ConstantInt *Cond;
-    if (!match(Pred->getTerminator(),
-               m_Br(m_ConstantInt(Cond), Taken, NotTaken)))
-      return false;
-    if (!Cond->getZExtValue())
-      std::swap(Taken, NotTaken);
-    if (Taken == Preheader)
-      return false;
-  }
-  assert(!pred_empty(Preheader) &&
-         "Preheader should have predecessors at this point!");
-  // All the predecessors have the loop preheader as not-taken target.
-  return true;
-}
-
-/// Remove a loop if it is dead.
-///
-/// A loop is considered dead if it does not impact the observable behavior of
-/// the program other than finite running time. This never removes a loop that
-/// might be infinite (unless it is never executed), as doing so could change
-/// the halting/non-halting nature of a program.
-///
-/// This entire process relies pretty heavily on LoopSimplify form and LCSSA in
-/// order to make various safety checks work.
-///
-/// \returns true if any changes were made. This may mutate the loop even if it
-/// is unable to delete it due to hoisting trivially loop invariant
-/// instructions out of the loop.
-static LoopDeletionResult deleteLoopIfDead(Loop *L, DominatorTree &DT,
-                                           ScalarEvolution &SE, LoopInfo &LI) {
-  assert(L->isLCSSAForm(DT) && "Expected LCSSA!");
-
-  // We can only remove the loop if there is a preheader that we can branch from
-  // after removing it. Also, if LoopSimplify form is not available, stay out
-  // of trouble.
-  BasicBlock *Preheader = L->getLoopPreheader();
-  if (!Preheader || !L->hasDedicatedExits()) {
-    LLVM_DEBUG(
-        dbgs()
-        << "Deletion requires Loop with preheader and dedicated exits.\n");
-    return LoopDeletionResult::Unmodified;
-  }
-  // We can't remove loops that contain subloops.  If the subloops were dead,
-  // they would already have been removed in earlier executions of this pass.
-  if (L->begin() != L->end()) {
-    LLVM_DEBUG(dbgs() << "Loop contains subloops.\n");
-    return LoopDeletionResult::Unmodified;
-  }
-
-
-  BasicBlock *ExitBlock = L->getUniqueExitBlock();
-
-  if (ExitBlock && isLoopNeverExecuted(L)) {
-    LLVM_DEBUG(dbgs() << "Loop is proven to never execute, delete it!");
-    // Set incoming value to undef for phi nodes in the exit block.
-    for (PHINode &P : ExitBlock->phis()) {
-      std::fill(P.incoming_values().begin(), P.incoming_values().end(),
-                UndefValue::get(P.getType()));
-    }
-    deleteDeadLoop(L, &DT, &SE, &LI);
-    ++NumDeleted;
-    return LoopDeletionResult::Deleted;
-  }
-
-  // The remaining checks below are for a loop being dead because all statements
-  // in the loop are invariant.
-  SmallVector<BasicBlock *, 4> ExitingBlocks;
-  L->getExitingBlocks(ExitingBlocks);
-
-  // We require that the loop only have a single exit block.  Otherwise, we'd
-  // be in the situation of needing to be able to solve statically which exit
-  // block will be branched to, or trying to preserve the branching logic in
-  // a loop invariant manner.
-  if (!ExitBlock) {
-    LLVM_DEBUG(dbgs() << "Deletion requires single exit block\n");
-    return LoopDeletionResult::Unmodified;
-  }
-  // Finally, we have to check that the loop really is dead.
-  bool Changed = false;
-  if (!isLoopDead(L, SE, ExitingBlocks, ExitBlock, Changed, Preheader)) {
-    LLVM_DEBUG(dbgs() << "Loop is not invariant, cannot delete.\n");
-    return Changed ? LoopDeletionResult::Modified
-                   : LoopDeletionResult::Unmodified;
-  }
-
-  // Don't remove loops for which we can't solve the trip count.
-  // They could be infinite, in which case we'd be changing program behavior.
-  const SCEV *S = SE.getMaxBackedgeTakenCount(L);
-  if (isa<SCEVCouldNotCompute>(S)) {
-    LLVM_DEBUG(dbgs() << "Could not compute SCEV MaxBackedgeTakenCount.\n");
-    return Changed ? LoopDeletionResult::Modified
-                   : LoopDeletionResult::Unmodified;
-  }
-
-  LLVM_DEBUG(dbgs() << "Loop is invariant, delete it!");
-  deleteDeadLoop(L, &DT, &SE, &LI);
-  ++NumDeleted;
-
-  return LoopDeletionResult::Deleted;
-}
-
-PreservedAnalyses LoopDeletionPass::run(Loop &L, LoopAnalysisManager &AM,
-                                        LoopStandardAnalysisResults &AR,
-                                        LPMUpdater &Updater) {
-
-  LLVM_DEBUG(dbgs() << "Analyzing Loop for deletion: ");
-  LLVM_DEBUG(L.dump());
-  std::string LoopName = L.getName();
-  auto Result = deleteLoopIfDead(&L, AR.DT, AR.SE, AR.LI);
-  if (Result == LoopDeletionResult::Unmodified)
-    return PreservedAnalyses::all();
-
-  if (Result == LoopDeletionResult::Deleted)
-    Updater.markLoopAsDeleted(L, LoopName);
-
-  return getLoopPassPreservedAnalyses();
-}
-
-namespace {
-class LoopDeletionLegacyPass : public LoopPass {
-public:
-  static char ID; // Pass ID, replacement for typeid
-  LoopDeletionLegacyPass() : LoopPass(ID) {
-    initializeLoopDeletionLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  // Possibly eliminate loop L if it is dead.
-  bool runOnLoop(Loop *L, LPPassManager &) override;
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    getLoopAnalysisUsage(AU);
-  }
-};
-}
-
-char LoopDeletionLegacyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(LoopDeletionLegacyPass, "loop-deletion",
-                      "Delete dead loops", false, false)
-INITIALIZE_PASS_DEPENDENCY(LoopPass)
-INITIALIZE_PASS_END(LoopDeletionLegacyPass, "loop-deletion",
-                    "Delete dead loops", false, false)
-
-Pass *llvm::createLoopDeletionPass() { return new LoopDeletionLegacyPass(); }
-
-bool LoopDeletionLegacyPass::runOnLoop(Loop *L, LPPassManager &LPM) {
-  if (skipLoop(L))
-    return false;
-  DominatorTree &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  ScalarEvolution &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
-  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
-
-  LLVM_DEBUG(dbgs() << "Analyzing Loop for deletion: ");
-  LLVM_DEBUG(L->dump());
-
-  LoopDeletionResult Result = deleteLoopIfDead(L, DT, SE, LI);
-
-  if (Result == LoopDeletionResult::Deleted)
-    LPM.markLoopAsDeleted(*L);
-
-  return Result != LoopDeletionResult::Unmodified;
-}