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/Transforms/Instrumentation/ThreadSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
index b84f391..17168a7 100644
--- a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
@@ -502,7 +502,7 @@
   if (Idx < 0)
     return false;
   if (IsWrite && isVtableAccess(I)) {
-    DEBUG(dbgs() << "  VPTR : " << *I << "\n");
+    LLVM_DEBUG(dbgs() << "  VPTR : " << *I << "\n");
     Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
     // StoredValue may be a vector type if we are storing several vptrs at once.
     // In this case, just take the first element of the vector since this is