Fix misc. small issues with debug visualization.

Detailed bug report:
http://llvm.org/bugs/show_bug.cgi?id=3873

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67768 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CompilerDriver/CompilationGraph.cpp b/lib/CompilerDriver/CompilationGraph.cpp
index b8a66e1..6112cfe 100644
--- a/lib/CompilerDriver/CompilationGraph.cpp
+++ b/lib/CompilerDriver/CompilationGraph.cpp
@@ -465,6 +465,9 @@
   // Check for cycles.
   ret += this->CheckCycles();
 
+  if (!ret)
+    std::cerr << "check-graph: no errors found.\n";
+
   return ret;
 }
 
@@ -520,7 +523,9 @@
   std::ofstream O("compilation-graph.dot");
 
   if (O.good()) {
-    llvm::WriteGraph(this, "compilation-graph");
+    std::cerr << "Writing 'compilation-graph.dot' file...";
+    llvm::WriteGraph(O, this);
+    std::cerr << "done.\n";
     O.close();
   }
   else {