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/WebAssembly/WebAssemblyArgumentMove.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyArgumentMove.cpp
index 3c17b2e..7c8a631 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyArgumentMove.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyArgumentMove.cpp
@@ -68,7 +68,7 @@
 }
 
 bool WebAssemblyArgumentMove::runOnMachineFunction(MachineFunction &MF) {
-  DEBUG({
+  LLVM_DEBUG({
     dbgs() << "********** Argument Move **********\n"
            << "********** Function: " << MF.getName() << '\n';
   });