Don't use <sstream> in Streams.h but <iosfwd> instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32340 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/SystemUtils.cpp b/lib/Support/SystemUtils.cpp
index 1d2c108..30b9f8d 100644
--- a/lib/Support/SystemUtils.cpp
+++ b/lib/Support/SystemUtils.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Support/SystemUtils.h"
 #include "llvm/System/Process.h"
 #include "llvm/System/Program.h"
+#include <ostream>
 using namespace llvm;
 
 bool llvm::CheckBytecodeOutputToConsole(std::ostream* stream_to_check,