fix compiler warnings for unused variables and functions.

See commits ae97fa16 and a178ea1b.

src/libespeak-ng/compiledata.c

 static int count_frames = 0;
 static int error_count = 0;
 static int resample_count = 0;
-static int resample_fails = 0;
 static int then_count = 0;
 static bool after_if = false;
 
 int item_terminator;
 char item_string[N_ITEM_STRING];
 
-static int ref_sorter(char **a, char **b)
-{
-	int ix;
-
-	REF_HASH_TAB *p1 = (REF_HASH_TAB *)(*a);
-	REF_HASH_TAB *p2 = (REF_HASH_TAB *)(*b);
-
-	ix = strcoll(p1->string, p2->string);
-	if (ix != 0)
-		return ix;
-
-	ix = p1->ph_table - p2->ph_table;
-	if (ix != 0)
-		return ix;
-
-	return p1->ph_mnemonic - p2->ph_mnemonic;
-}
-
 static void error(const char *format, ...)
 {
 	va_list args;
 	int max = 0;
 	int length;
 	int sr1, sr2;
-	int len;
 	int scale_factor = 0;
 
 	fseek(f, 24, SEEK_SET);

src/libespeak-ng/soundicon.c

 	if ((f = fopen(fname, "rb")) != NULL) {
 		int ix;
 		int header[3];
-		char command[sizeof(fname2)+sizeof(fname2)+40];
 
 		if (fseek(f, 20, SEEK_SET) == -1) {
 			int error = errno;