Use alternative fix to the issue in aiff_extract_codebook.c

tools/Makefile

@@ -1,9 +1,6 @@
 CC := gcc
 CXX := g++
 CFLAGS := -I../include -I. -Wall -Wextra -Wno-unused-parameter -pedantic -std=c99 -O2 -s
-ifeq ($(shell uname),Darwin)
-CFLAGS += -Wno-error=implicit-function-declaration
-endif
 LDFLAGS := -lm
 PROGRAMS := n64graphics n64graphics_ci mio0 n64cksum textconv patch_libultra_math aifc_decode aiff_extract_codebook vadpcm_enc tabledesign extract_data_for_mio skyconv
 

tools/aiff_extract_codebook.c

@@ -26,6 +26,11 @@ typedef unsigned int u32;
 #define NORETURN __attribute__((noreturn))
 #define UNUSED __attribute__((unused))
 
+#ifdef __APPLE__
+// even with -std=gnu99 vsnprintf seems to not be defined in stdio.h, why?
+extern int vsnprintf(char * __restrict, size_t, const char * __restrict, va_list);
+#endif
+
 typedef struct
 {
     u32 start;