Fixed many incompatible pointer warnings; add tcc specific debugging flags to makefile

source/engine/sound/dsp.h

@@ -153,4 +153,6 @@ void dsp_mono(void *p, short *out, int n);
 
 void dsp_bitcrush(void *p, short *out, int n);
 
+void dsp_run(struct dsp_filter filter, short *out, int n);
+
 #endif

source/engine/sound/mix.c

@@ -2,6 +2,8 @@
 #include "stddef.h"
 #include "time.h"
 #include "sound.h"
+#include "dsp.h"
+#include <string.h>
 
 static struct bus bus[256];
 short mastermix[BUF_FRAMES*CHANNELS];