Replace OStream with std::ostream.

src/compiler/change-lowering-unittest.cc

Index: src/compiler/change-lowering-unittest.cc
diff --git a/src/compiler/change-lowering-unittest.cc b/src/compiler/change-lowering-unittest.cc
index 994027a83caed7ce5263d43b6e1907c1ff994132..7b0fab21f4e069c6996d8571bc72b417a2e343b8 100644
--- a/src/compiler/change-lowering-unittest.cc
+++ b/src/compiler/change-lowering-unittest.cc
@@ -20,14 +20,6 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
-// TODO(bmeurer): Find a new home for these functions.
-inline std::ostream& operator<<(std::ostream& os, const MachineType& type) {
-  OStringStream ost;
-  ost << type;
-  return os << ost.c_str();
-}
-
-
 class ChangeLoweringTest : public GraphTest {
  public:
   ChangeLoweringTest() : simplified_(zone()) {}