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/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index c3175dd..c8099c8 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1724,7 +1724,7 @@
       return GMP;
     }
   
-  cerr << "no GCMetadataPrinter registered for GC: " << Name << "\n";
+  errs() << "no GCMetadataPrinter registered for GC: " << Name << "\n";
   llvm_unreachable(0);
 }