Modernize code

Can compile with arm-none-eabi-gcc 8.3.0
gbafix correctly handles ELF input

include/gba/defines.h

@@ -6,9 +6,20 @@
 #define TRUE  1
 #define FALSE 0
 
+#define BSS_DATA   __attribute__((section(".bss")))
+#if MODERN
+#define IWRAM_DATA
+#else
 #define IWRAM_DATA __attribute__((section("iwram_data")))
+#endif
 #define EWRAM_DATA __attribute__((section("ewram_data")))
 
+#if MODERN
+#define NOINLINE __attribute__((noinline))
+#else
+#define NOINLINE
+#endif
+
 #define ALIGNED(n) __attribute__((aligned(n)))
 
 #define SOUND_INFO_PTR (*(struct SoundInfo **)0x3007FF0)