Remove more iostream header includes. Needed to implement a "FlushStream"
function to flush a specified std::ostream.

llvm-svn: 51705
diff --git a/llvm/lib/Support/Streams.cpp b/llvm/lib/Support/Streams.cpp
index 122955f..cf6cfeb 100644
--- a/llvm/lib/Support/Streams.cpp
+++ b/llvm/lib/Support/Streams.cpp
@@ -19,3 +19,12 @@
 OStream llvm::cout(std::cout);
 OStream llvm::cerr(std::cerr);
 IStream llvm::cin(std::cin);
+
+namespace llvm {
+
+/// FlushStream - Function called by BaseStream to flush an ostream.
+void FlushStream(std::ostream &S) {
+  S << std::flush;
+}
+
+} // end anonymous namespace