Fix -Wstrict-prototypes -Wmissing-prototypes warnings.

The files src/flac/encode.c and src/libFLAC/stream_encoder.c use
functions in libFLAC that are marked as 'unpublished debug routines'.
This patch moves these functions to new file include/share/private.h
and marks them as 'unpublished debug routines'.

include/share/Makefile.am

@@ -9,6 +9,7 @@ EXTRA_DIST = \
 	getopt.h \
 	grabbag.h \
 	macros.h \
+	private.h \
 	replaygain_analysis.h \
 	replaygain_synthesis.h \
 	utf8.h

include/share/private.h

@@ -0,0 +1,45 @@
+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2013  Xiph.org Foundation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Xiph.org Foundation nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef FLAC__SHARE__PRIVATE_H
+#define FLAC__SHARE__PRIVATE_H
+
+/*
+ * Unpublished debug routines from libFLAC> This should not be used from any
+ * client code other than code shipped with the FLAC sources.
+ */
+FLAC__bool FLAC__stream_encoder_disable_constant_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
+FLAC__bool FLAC__stream_encoder_disable_fixed_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
+FLAC__bool FLAC__stream_encoder_disable_verbatim_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
+FLAC__bool FLAC__stream_encoder_set_do_md5(FLAC__StreamEncoder *encoder, FLAC__bool value);
+FLAC__bool FLAC__stream_encoder_get_do_md5(const FLAC__StreamEncoder *encoder);
+
+#endif /* FLAC__SHARE__PRIVATE_H */

src/flac/encode.c

@@ -31,6 +31,7 @@
 #include "share/alloc.h"
 #include "share/grabbag.h"
 #include "share/compat.h"
+#include "share/private.h"
 #include "encode.h"
 
 #ifdef min
@@ -120,14 +121,6 @@ static FLAC__int32 in_[FLAC__MAX_CHANNELS][CHUNK_OF_SAMPLES];
 static FLAC__int32 *input_[FLAC__MAX_CHANNELS];
 
 
-/*
- * unpublished debug routines from the FLAC libs
- */
-extern FLAC__bool FLAC__stream_encoder_disable_constant_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
-extern FLAC__bool FLAC__stream_encoder_disable_fixed_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
-extern FLAC__bool FLAC__stream_encoder_disable_verbatim_subframes(FLAC__StreamEncoder *encoder, FLAC__bool value);
-extern FLAC__bool FLAC__stream_encoder_set_do_md5(FLAC__StreamEncoder *encoder, FLAC__bool value);
-
 /*
  * local routines
  */

src/libFLAC/stream_encoder.c

@@ -40,8 +40,6 @@
 #include <sys/types.h> /* for off_t */
 #include "FLAC/assert.h"
 #include "FLAC/stream_decoder.h"
-#include "share/alloc.h"
-#include "share/compat.h"
 #include "protected/stream_encoder.h"
 #include "private/bitwriter.h"
 #include "private/bitmath.h"
@@ -59,6 +57,9 @@
 #endif
 #include "private/stream_encoder_framing.h"
 #include "private/window.h"
+#include "share/alloc.h"
+#include "share/compat.h"
+#include "share/private.h"
 
 
 /* Exact Rice codeword length calculation is off by default.  The simple