make this file self-contained


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
index 6d7b174..550459e 100644
--- a/include/llvm/Bitcode/BitstreamReader.h
+++ b/include/llvm/Bitcode/BitstreamReader.h
@@ -16,6 +16,7 @@
 #define BITSTREAM_READER_H
 
 #include "llvm/Bitcode/BitCodes.h"
+#include <vector>
 
 namespace llvm {