[AVR] Add missing #includes

A previous change seems to have remove #includes from header files. This
fixes the build.

llvm-svn: 294427

llvm/lib/Target/AVR/MCTargetDesc/AVRELFStreamer.cpp

@@ -1,5 +1,7 @@
 #include "AVRELFStreamer.h"
 
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/FormattedStream.h"
 

llvm/lib/Target/AVR/MCTargetDesc/AVRMCCodeEmitter.cpp

@@ -25,6 +25,7 @@
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"
 
 #define DEBUG_TYPE "mccodeemitter"