Rename DEBUG macro to LLVM_DEBUG.
    
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
diff --git a/llvm/lib/CodeGen/TailDuplicator.cpp b/llvm/lib/CodeGen/TailDuplicator.cpp
index b4ee877..b118c17 100644
--- a/llvm/lib/CodeGen/TailDuplicator.cpp
+++ b/llvm/lib/CodeGen/TailDuplicator.cpp
@@ -262,7 +262,7 @@
   bool MadeChange = false;
 
   if (PreRegAlloc && TailDupVerify) {
-    DEBUG(dbgs() << "\n*** Before tail-duplicating\n");
+    LLVM_DEBUG(dbgs() << "\n*** Before tail-duplicating\n");
     VerifyPHIs(*MF, true);
   }
 
@@ -718,8 +718,8 @@
       continue;
 
     Changed = true;
-    DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB
-                 << "From simple Succ: " << *TailBB);
+    LLVM_DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB
+                      << "From simple Succ: " << *TailBB);
 
     MachineBasicBlock *NewTarget = *TailBB->succ_begin();
     MachineBasicBlock *NextBB = PredBB->getNextNode();
@@ -799,8 +799,8 @@
                                    MachineBasicBlock *ForcedLayoutPred,
                                    SmallVectorImpl<MachineBasicBlock *> &TDBBs,
                                    SmallVectorImpl<MachineInstr *> &Copies) {
-  DEBUG(dbgs() << "\n*** Tail-duplicating " << printMBBReference(*TailBB)
-               << '\n');
+  LLVM_DEBUG(dbgs() << "\n*** Tail-duplicating " << printMBBReference(*TailBB)
+                    << '\n');
 
   DenseSet<unsigned> UsedByPhi;
   getRegsUsedByPHIs(*TailBB, &UsedByPhi);
@@ -830,8 +830,8 @@
     if (IsLayoutSuccessor)
       continue;
 
-    DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB
-                 << "From Succ: " << *TailBB);
+    LLVM_DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB
+                      << "From Succ: " << *TailBB);
 
     TDBBs.push_back(PredBB);
 
@@ -893,8 +893,8 @@
       (!PriorTBB || PriorTBB == TailBB) &&
       TailBB->pred_size() == 1 &&
       !TailBB->hasAddressTaken()) {
-    DEBUG(dbgs() << "\nMerging into block: " << *PrevBB
-                 << "From MBB: " << *TailBB);
+    LLVM_DEBUG(dbgs() << "\nMerging into block: " << *PrevBB
+                      << "From MBB: " << *TailBB);
     // There may be a branch to the layout successor. This is unlikely but it
     // happens. The correct thing to do is to remove the branch before
     // duplicating the instructions in all cases.
@@ -999,7 +999,7 @@
     MachineBasicBlock *MBB,
     function_ref<void(MachineBasicBlock *)> *RemovalCallback) {
   assert(MBB->pred_empty() && "MBB must be dead!");
-  DEBUG(dbgs() << "\nRemoving MBB: " << *MBB);
+  LLVM_DEBUG(dbgs() << "\nRemoving MBB: " << *MBB);
 
   if (RemovalCallback)
     (*RemovalCallback)(MBB);