Add debug output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127959 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 6feae47..c1d8272 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -1265,6 +1265,7 @@
   // Wait until the second time, when all smaller ranges have been allocated.
   // This gives a better picture of the interference to split around.
   if (Stage == RS_Original) {
+    DEBUG(dbgs() << "wait for second round\n");
     NewVRegs.push_back(&VirtReg);
     return 0;
   }