Rename all functions imported from musl

This is to avoid conflicting with libraries, which occurred in the mingw builds

include/extern/getopt.h

@@ -36,7 +36,7 @@ struct option {
 	int val;
 };
 
-int getopt_long_only(int, char **, const char *, const struct option *, int *);
+int musl_getopt_long_only(int, char **, const char *, const struct option *, int *);
 
 #define no_argument        0
 #define required_argument  1