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/Target/X86/X86FixupBWInsts.cpp b/llvm/lib/Target/X86/X86FixupBWInsts.cpp
index 46f1382..d9bf60c 100644
--- a/llvm/lib/Target/X86/X86FixupBWInsts.cpp
+++ b/llvm/lib/Target/X86/X86FixupBWInsts.cpp
@@ -155,13 +155,13 @@
   MLI = &getAnalysis<MachineLoopInfo>();
   LiveRegs.init(TII->getRegisterInfo());
 
-  DEBUG(dbgs() << "Start X86FixupBWInsts\n";);
+  LLVM_DEBUG(dbgs() << "Start X86FixupBWInsts\n";);
 
   // Process all basic blocks.
   for (auto &MBB : MF)
     processBasicBlock(MF, MBB);
 
-  DEBUG(dbgs() << "End X86FixupBWInsts\n";);
+  LLVM_DEBUG(dbgs() << "End X86FixupBWInsts\n";);
 
   return true;
 }