convert LoopInfo.h and GraphWriter.h to use raw_ostream


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79836 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp
index ee03556..0007ade 100644
--- a/lib/Analysis/LoopPass.cpp
+++ b/lib/Analysis/LoopPass.cpp
@@ -272,7 +272,7 @@
 
 /// Print passes managed by this manager
 void LPPassManager::dumpPassStructure(unsigned Offset) {
-  llvm::cerr << std::string(Offset*2, ' ') << "Loop Pass Manager\n";
+  errs().indent(Offset*2) << "Loop Pass Manager\n";
   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
     Pass *P = getContainedPass(Index);
     P->dumpPassStructure(Offset + 1);