Header hygiene: remove using directive and #undef DEBUG_TYPE once we're done.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214263 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineRegionInfo.cpp

@@ -4,6 +4,8 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/RegionInfoImpl.h"
 
+#define DEBUG_TYPE "region"
+
 using namespace llvm;
 
 STATISTIC(numMachineRegions,       "The # of machine regions");