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/SIOptimizeExecMaskingPreRA.cpp b/llvm/lib/Target/AMDGPU/SIOptimizeExecMaskingPreRA.cpp
index b7bb80a..c9e3e56 100644
--- a/llvm/lib/Target/AMDGPU/SIOptimizeExecMaskingPreRA.cpp
+++ b/llvm/lib/Target/AMDGPU/SIOptimizeExecMaskingPreRA.cpp
@@ -143,7 +143,8 @@
               I->hasUnmodeledSideEffects() || I->hasOrderedMemoryRef())
             break;
 
-          DEBUG(dbgs() << "Removing no effect instruction: " << *I << '\n');
+          LLVM_DEBUG(dbgs()
+                     << "Removing no effect instruction: " << *I << '\n');
 
           for (auto &Op : I->operands()) {
             if (Op.isReg())
@@ -193,7 +194,7 @@
         !getOrExecSource(*NextLead, *TII, MRI))
       continue;
 
-    DEBUG(dbgs() << "Redundant EXEC = S_OR_B64 found: " << *Lead << '\n');
+    LLVM_DEBUG(dbgs() << "Redundant EXEC = S_OR_B64 found: " << *Lead << '\n');
 
     auto SaveExec = getOrExecSource(*Lead, *TII, MRI);
     unsigned SaveExecReg = getOrNonExecReg(*Lead, *TII);
@@ -224,7 +225,7 @@
         break;
       }
 
-      DEBUG(dbgs() << "Redundant EXEC COPY: " << *SaveExec << '\n');
+      LLVM_DEBUG(dbgs() << "Redundant EXEC COPY: " << *SaveExec << '\n');
     }
 
     if (SafeToReplace) {