gpu_unai: switch back to older DIV_MULTINV behavior

caused polygon "cracks" if compiled on gcc 10.2 (devkitARM release 55),
but seems ok on gcc 11.4 or gcc 14.2 (devkitARM release 65)

#852

Author: notaz

Makefile.libretro

@@ -355,7 +355,8 @@ else ifeq ($(platform), ctr)
 	endif
 	TARGET := $(TARGET_NAME)_libretro_ctr.a
 	CFLAGS += -DARM11 -D_3DS -D__3DS__
-	CFLAGS += -DNO_DYLIB -DGPU_UNAI_USE_FLOATMATH -DGPU_UNAI_USE_FLOAT_DIV_MULTINV
+	CFLAGS += -DGPU_UNAI_USE_FLOATMATH -DGPU_UNAI_USE_FLOAT_DIV_MULTINV
+	CFLAGS += -DGPU_UNAI_USE_FLOAT_DIV_MULTINV_FOR_ONE # needed on some compilers?
 	CFLAGS += -march=armv6k -mtune=mpcore -mfloat-abi=hard -marm -mfpu=vfp -mtp=soft
 	CFLAGS += -mword-relocations
 	CFLAGS += -fomit-frame-pointer
@@ -367,6 +368,7 @@ else ifeq ($(platform), ctr)
 	CFLAGS += -DHAVE_UNISTD_H
 	CFLAGS += -DZ7_DECL_Int32_AS_long
 	CFLAGS += -DUSE_CTRULIB_2
+	CFLAGS += -DNO_DYLIB
 
 	OBJS += deps/arm-mem/memcpymove-v6l.o
 	OBJS += deps/arm-mem/memset-v6l.o