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/AMDGPU/AMDGPUTargetTransformInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
index 3ea7a82..ce17f02 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
@@ -124,8 +124,9 @@
             continue;
           if (dependsOnLocalPhi(L, Br->getCondition())) {
             UP.Threshold += UnrollThresholdIf;
-            DEBUG(dbgs() << "Set unroll threshold " << UP.Threshold
-                         << " for loop:\n" << *L << " due to " << *Br << '\n');
+            LLVM_DEBUG(dbgs() << "Set unroll threshold " << UP.Threshold
+                              << " for loop:\n"
+                              << *L << " due to " << *Br << '\n');
             if (UP.Threshold >= MaxBoost)
               return;
           }
@@ -201,8 +202,9 @@
       // Don't use the maximum allowed value here as it will make some
       // programs way too big.
       UP.Threshold = Threshold;
-      DEBUG(dbgs() << "Set unroll threshold " << Threshold << " for loop:\n"
-                   << *L << " due to " << *GEP << '\n');
+      LLVM_DEBUG(dbgs() << "Set unroll threshold " << Threshold
+                        << " for loop:\n"
+                        << *L << " due to " << *GEP << '\n');
       if (UP.Threshold >= MaxBoost)
         return;
     }