fix aggressive loop optimizations

Previously, aggressive loop optimizations with a new compiler were not
possible due to undefined behaviour at end of arrays.

A macro "UBFIX" is added to allow ifdefs for fixes which resolve
undefined behavior. For example newer GCC versions will detect various
bugs in the original game code and will otherwise not compile with -Werror.

src/berry_blender.c

@@ -2202,6 +2202,11 @@ static s16 sub_8081BD4(void)
     return sUnknown_03000E06;
 }
 
+#if MODERN
+// TODO remove this as soon as the code below is understood
+// add a UBFIX if required (code buggy?)
+__attribute__((optimize("no-aggressive-loop-optimizations")))
+#endif
 static void Blender_CalculatePokeblock(struct BlenderBerry *berries, struct Pokeblock *pokeblock, u8 playersNo, u8 *flavors, u16 maxRPM)
 {
     s32 i, j;