midx: make some functions non-static

In a subsequent commit, pack-revindex.c will become responsible for
sorting a list of objects in the "MIDX pack order" (which will be
defined in the following patch). To do so, it will need to be know the
pack identifier and offset within that pack for each object in the MIDX.

The MIDX code already has functions for doing just that
(nth_midxed_offset() and nth_midxed_pack_int_id()), but they are
statically declared.

Since there is no reason that they couldn't be exposed publicly, and
because they are already doing exactly what the caller in
pack-revindex.c will want, expose them publicly so that they can be
reused there.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

midx.c

@@ -239,7 +239,7 @@ struct object_id *nth_midxed_object_oid(struct object_id *oid,
 	return oid;
 }
 
-static off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
+off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
 {
 	const unsigned char *offset_data;
 	uint32_t offset32;
@@ -258,7 +258,7 @@ static off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
 	return offset32;
 }
 
-static uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos)
+uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos)
 {
 	return get_be32(m->chunk_object_offsets +
 			(off_t)pos * MIDX_CHUNK_OFFSET_WIDTH);

midx.h

@@ -40,6 +40,8 @@ struct multi_pack_index {
 struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local);
 int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id);
 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result);
+off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos);
+uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos);
 struct object_id *nth_midxed_object_oid(struct object_id *oid,
 					struct multi_pack_index *m,
 					uint32_t n);