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/PowerPC/PPCPreEmitPeephole.cpp b/llvm/lib/Target/PowerPC/PPCPreEmitPeephole.cpp
index d524c35..1892d1e 100644
--- a/llvm/lib/Target/PowerPC/PPCPreEmitPeephole.cpp
+++ b/llvm/lib/Target/PowerPC/PPCPreEmitPeephole.cpp
@@ -67,8 +67,8 @@
           if (TII->convertToImmediateForm(MI, &DefMIToErase)) {
             Changed = true;
             NumRRConvertedInPreEmit++;
-            DEBUG(dbgs() << "Converted instruction to imm form: ");
-            DEBUG(MI.dump());
+            LLVM_DEBUG(dbgs() << "Converted instruction to imm form: ");
+            LLVM_DEBUG(MI.dump());
             if (DefMIToErase) {
               InstrsToErase.push_back(DefMIToErase);
             }
@@ -76,8 +76,8 @@
         }
       }
       for (MachineInstr *MI : InstrsToErase) {
-        DEBUG(dbgs() << "PPC pre-emit peephole: erasing instruction: ");
-        DEBUG(MI->dump());
+        LLVM_DEBUG(dbgs() << "PPC pre-emit peephole: erasing instruction: ");
+        LLVM_DEBUG(MI->dump());
         MI->eraseFromParent();
         NumRemovedInPreEmit++;
       }