[ARC] Add ARC backend.

Add the ARC backend as an experimental target to lib/Target.
Reviewed at: https://reviews.llvm.org/D36331

llvm-svn: 311667
diff --git a/llvm/lib/Target/ARC/ARCTargetStreamer.h b/llvm/lib/Target/ARC/ARCTargetStreamer.h
new file mode 100644
index 0000000..29fdfda
--- /dev/null
+++ b/llvm/lib/Target/ARC/ARCTargetStreamer.h
@@ -0,0 +1,25 @@
+//===- ARCTargetStreamer.h - ARC Target Streamer ----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_ARC_ARCTARGETSTREAMER_H
+#define LLVM_LIB_TARGET_ARC_ARCTARGETSTREAMER_H
+
+#include "llvm/MC/MCStreamer.h"
+
+namespace llvm {
+
+class ARCTargetStreamer : public MCTargetStreamer {
+public:
+  ARCTargetStreamer(MCStreamer &S);
+  ~ARCTargetStreamer() override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_ARC_ARCTARGETSTREAMER_H