[MIR] Print on the given output instead of stderr.

Currently the MIR framework prints all its outputs (errors and actual
representation) on stderr.

This patch fixes that by printing the regular output in the output
specified with -o.

Differential Revision: http://reviews.llvm.org/D22251

llvm-svn: 275314
diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
index e62c94d..9eb43d2 100644
--- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
@@ -194,7 +194,7 @@
     return true;
 
   if (StopAfter) {
-    PM.add(createPrintMIRPass(errs()));
+    PM.add(createPrintMIRPass(Out));
     return false;
   }