Consistently use uppercase hex digits

src/extern/getopt.c

@@ -82,7 +82,7 @@ static int getopt(int argc, char *argv[], char const *optstring)
 	k = mbtowc(&c, argv[musl_optind] + musl_optpos, MB_LEN_MAX);
 	if (k < 0) {
 		k = 1;
-		c = 0xfffd; /* replacement char */
+		c = 0xFFFD; /* replacement char */
 	}
 	optchar = argv[musl_optind] + musl_optpos;
 	musl_optpos += k;

src/extern/utf8decoder.c

@@ -43,8 +43,8 @@ uint32_t decode(uint32_t *state, uint32_t *codep, uint8_t byte)
 	uint32_t type = utf8d[byte];
 
 	*codep = (*state != 0) ?
-			(byte & 0x3fu) | (*codep << 6) :
-			(0xff >> type) & (byte);
+			(byte & 0x3FU) | (*codep << 6) :
+			(0xFF >> type) & (byte);
 
 	*state = utf8d[256 + *state * 16 + type];
 	return *state;