Add missing includes. make_unique proliferated everywhere.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230909 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -9,6 +9,7 @@
 
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "BitcodeReader.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"