When printing DS nodes, print the mergemap index as well to allow easier
debugging of merging process.

llvm-svn: 4010
diff --git a/llvm/lib/Analysis/DataStructure/Printer.cpp b/llvm/lib/Analysis/DataStructure/Printer.cpp
index f6c36e4..528652b 100644
--- a/llvm/lib/Analysis/DataStructure/Printer.cpp
+++ b/llvm/lib/Analysis/DataStructure/Printer.cpp
@@ -100,7 +100,7 @@
     O << "|{";
     for (unsigned i = 0; i < getSize(); ++i) {
       if (i) O << "|";
-      O << "<g" << i << ">";
+      O << "<g" << i << ">" << (int)MergeMap[i];
     }
     O << "}";
   }