tweaks to build libs as DLLs under windows

src/share/getopt.c

@@ -125,7 +125,7 @@
    Also, when `ordering' is RETURN_IN_ORDER,
    each non-option ARGV-element is returned here.  */
 
-char *FLAC__share__optarg;
+GETOPT_API char *FLAC__share__optarg;
 
 /* Index in ARGV of the next element to be scanned.
    This is used for communication to and from the caller
@@ -140,7 +140,7 @@ char *FLAC__share__optarg;
    how much of ARGV has been scanned so far.  */
 
 /* 1003.2 says this must be 1 before any call.  */
-int FLAC__share__optind = 1;
+GETOPT_API int FLAC__share__optind = 1;
 
 /* Formerly, initialization of getopt depended on FLAC__share__optind==0, which
    causes problems with re-calling getopt as programs generally don't
@@ -160,13 +160,13 @@ static char *nextchar;
 /* Callers store zero here to inhibit the error message
    for unrecognized options.  */
 
-int FLAC__share__opterr = 1;
+GETOPT_API int FLAC__share__opterr = 1;
 
 /* Set to an option character which was unrecognized.
    This must be initialized on some systems to avoid linking in the
    system's own getopt implementation.  */
 
-int FLAC__share__optopt = '?';
+GETOPT_API int FLAC__share__optopt = '?';
 
 /* Describe how to deal with options that follow non-option ARGV-elements.
 
@@ -522,7 +522,7 @@ FLAC__share___getopt_initialize (argc, argv, optstring)
    If LONG_ONLY is nonzero, '-' as well as '--' can introduce
    long-named options.  */
 
-int
+GETOPT_API int
 FLAC__share___getopt_internal (argc, argv, optstring, longopts, longind, long_only)
      int argc;
      char *const *argv;
@@ -978,7 +978,7 @@ FLAC__share___getopt_internal (argc, argv, optstring, longopts, longind, long_on
   }
 }
 
-int
+GETOPT_API int
 FLAC__share__getopt (argc, argv, optstring)
      int argc;
      char *const *argv;

src/share/getopt1.c

@@ -79,7 +79,7 @@
 #define NULL 0
 #endif
 
-int
+GETOPT_API int
 FLAC__share__getopt_long (argc, argv, options, long_options, opt_index)
      int argc;
      char *const *argv;
@@ -95,7 +95,7 @@ FLAC__share__getopt_long (argc, argv, options, long_options, opt_index)
    but does match a short option, it is parsed as a short option
    instead.  */
 
-int
+GETOPT_API int
 FLAC__share__getopt_long_only (argc, argv, options, long_options, opt_index)
      int argc;
      char *const *argv;

src/share/utf8.c

@@ -233,7 +233,7 @@ int iconvert(const char *fromcode, const char *tocode,
 
 static char *current_charset = 0; /* means "US-ASCII" */
 
-void convert_set_charset(const char *charset)
+UTF8_API void convert_set_charset(const char *charset)
 {
 
 #ifdef HAVE_LANGINFO_CODESET
@@ -296,7 +296,7 @@ static int convert_string(const char *fromcode, const char *tocode,
   return 3;
 }
 
-int utf8_encode(const char *from, char **to)
+UTF8_API int utf8_encode(const char *from, char **to)
 {
   char *charset;
 
@@ -306,7 +306,7 @@ int utf8_encode(const char *from, char **to)
   return convert_string(charset, "UTF-8", from, to, '#');
 }
 
-int utf8_decode(const char *from, char **to)
+UTF8_API int utf8_decode(const char *from, char **to)
 {
   char *charset;