MS VS inline/extern fix from Ben Alison plus comments.

Add explicit extern to functions that are locally declared inline
but which also have non-inline public prototypes.

It seems MS VS does not quite meet the C99 spec (section 6.7.4).

src/libFLAC/bitreader.c

@@ -1047,3 +1047,16 @@ FLAC__bool FLAC__bitreader_read_utf8_uint64(FLAC__BitReader *br, FLAC__uint64 *v
 	*val = v;
 	return true;
 }
+
+/* These functions a declared inline in this file but are also callable as
+ * externs from elsewhere.
+ * According to the C99 sepc, section 6.7.4, simply providing a function
+ * prototype in a header file without 'inline' and making the function inline
+ * in this file should be sufficient.
+ * Unfortunately, the Microsoft VS compiler doesn't pick them up externally. To
+ * fix that we add extern declarations here.
+ */
+extern FLAC__bool FLAC__bitreader_is_consumed_byte_aligned(const FLAC__BitReader *br);
+extern unsigned FLAC__bitreader_bits_left_for_byte_alignment(const FLAC__BitReader *br);
+extern unsigned FLAC__bitreader_get_input_bits_unconsumed(const FLAC__BitReader *br);
+extern FLAC__bool FLAC__bitreader_read_uint32_little_endian(FLAC__BitReader *br, FLAC__uint32 *val);

src/libFLAC/bitwriter.c

@@ -848,3 +848,16 @@ FLAC__bool FLAC__bitwriter_zero_pad_to_byte_boundary(FLAC__BitWriter *bw)
 	else
 		return true;
 }
+
+/* These functions a declared inline in this file but are also callable as
+ * externs from elsewhere.
+ * According to the C99 sepc, section 6.7.4, simply providing a function
+ * prototype in a header file without 'inline' and making the function inline
+ * in this file should be sufficient.
+ * Unfortunately, the Microsoft VS compiler doesn't pick them up externally. To
+ * fix that we add extern declarations here.
+ */
+extern FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, unsigned bits);
+extern FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, unsigned bits);
+extern FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter *bw, FLAC__uint32 val);
+extern FLAC__bool FLAC__bitwriter_write_byte_block(FLAC__BitWriter *bw, const FLAC__byte vals[], unsigned nvals);