Replace #include <iostream> with #include <ostream>
iostream is not actually necessary here, and it introduces unnecessary
static initializers.
diff --git a/src/google/protobuf/stubs/int128.cc b/src/google/protobuf/stubs/int128.cc
index d80c64f..3a36b4b 100644
--- a/src/google/protobuf/stubs/int128.cc
+++ b/src/google/protobuf/stubs/int128.cc
@@ -31,7 +31,7 @@
#include <google/protobuf/stubs/int128.h>
#include <iomanip>
-#include <iostream> // NOLINT(readability/streams)
+#include <ostream> // NOLINT(readability/streams)
#include <sstream>
namespace google {