Unbreak the MSVC build.

The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC.

llvm-svn: 124545

llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp

@@ -67,6 +67,7 @@
 #include "llvm/Support/CallSite.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 using namespace llvm;