Mention which standard replacements follow

compat/asprintf.c

 /*****************************************************************************
- * asprintf.c: asprintf() replacement
+ * asprintf.c: GNU asprintf() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/atof.c

 /*****************************************************************************
- * atof.c: atof replacement
+ * atof.c: C atof() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/atoll.c

 /*****************************************************************************
- * atoll.c: atoll replacement
+ * atoll.c: C atoll() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/lldiv.c

 /*****************************************************************************
- * lldiv.c: lldiv replacement
+ * lldiv.c: C lldiv() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strdup.c

 /*****************************************************************************
- * strdup.c: strdup replacement
+ * strdup.c: POSIX strdup() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strlcpy.c

 /*****************************************************************************
- * strlcpy.c: BSD strlcpy replacement
+ * strlcpy.c: BSD strlcpy() replacement
  *****************************************************************************
  * Copyright © 2006 Rémi Denis-Courmont
  *

compat/strndup.c

 /*****************************************************************************
- * strndup.c: strndup replacement
+ * strndup.c: POSIX strndup() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strnlen.c

 /*****************************************************************************
- * strnlen.c: strnlen replacement
+ * strnlen.c: POSIX strnlen() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strsep.c

 /*****************************************************************************
- * strsep.c: BSD strsep replacement
+ * strsep.c: BSD strsep() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strtof.c

 /*****************************************************************************
- * strtof.c: strtof replacement
+ * strtof.c: C strtof() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/strtoll.c

 /*****************************************************************************
- * strtoll.c: strtoll replacement
+ * strtoll.c: C strtoll() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *

compat/vasprintf.c

 /*****************************************************************************
- * vasprintf.c: vasprintf replacement
+ * vasprintf.c: GNU vasprintf() replacement
  *****************************************************************************
  * Copyright © 1998-2008 the VideoLAN project
  *