Moved ARM9.h from arm9 directory to src one and removed ARM9.c file

(and move the ARM9Mem declaration to GPU.c). It should fix the
compilation on Mac.

desmume/src/GPU.c

@@ -27,6 +27,8 @@
 
 #include "nds/video.h"
 
+ARM9_struct ARM9Mem;
+
 extern BOOL click;
 Screen MainScreen;
 Screen SubScreen;

desmume/src/GPU.h

@@ -22,7 +22,7 @@
 #ifndef GPU_H
 #define GPU_H
 
-#include "arm9/ARM9.h"
+#include "ARM9.h"
 #include <stdio.h>
 
 #ifdef __cplusplus

desmume/src/MMU.h

@@ -25,7 +25,7 @@
 #include "FIFO.h"
 #include "dscard.h"
 
-#include "arm9/ARM9.h"
+#include "ARM9.h"
 #include "nds/serial.h"
 #include "mc.h"
 

desmume/src/Makefile.am

@@ -11,7 +11,7 @@ libdesmume_a_SOURCES = \
         thumb_instructions.c thumb_instructions.h \
         mc.c mc.h \
 	GPU.c GPU.h \
-	arm9/ARM9.c arm9/ARM9.h \
+	ARM9.h \
         cflash.c cflash.h fs.h \
         saves.c saves.h
 libdesmume_a_LIBADD = fs-$(desmume_arch).$(OBJEXT)