Both `AArch64TargetParser.h` and `ARMTargetParser.h` refer to
`SmallVectorImpl` without directly including the header that defines
it, which works fine until nothing else happens to include it anyway.
#ifndef LLVM_SUPPORT_AARCH64TARGETPARSERCOMMON_H
#define LLVM_SUPPORT_AARCH64TARGETPARSERCOMMON_H
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ARMTargetParser.h"
#include <vector>
#ifndef LLVM_SUPPORT_ARMTARGETPARSER_H
#define LLVM_SUPPORT_ARMTARGETPARSER_H
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ARMBuildAttributes.h"
#include <vector>