Prune some includes

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153502 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86TargetObjectFile.cpp

@@ -14,7 +14,6 @@
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/Target/Mangler.h"
-#include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Dwarf.h"
 using namespace llvm;
 using namespace dwarf;