Clean up includes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160852 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index bd153a8..57979b3 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -14,8 +14,8 @@
 
 #include "AsmWriterInst.h"
 #include "CodeGenTarget.h"
-#include "StringToOffsetTable.h"
 #include "SequenceToOffsetTable.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"