Use // line comments not /* block comments

src/extern/getopt.cpp

@@ -1,6 +1,6 @@
-/* SPDX-License-Identifier: MIT */
+// SPDX-License-Identifier: MIT
 
-/* This implementation was taken from musl and modified for RGBDS */
+// This implementation was taken from musl and modified for RGBDS
 
 #include "extern/getopt.hpp"
 
@@ -57,7 +57,7 @@ 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;