MINOR: stream/htx: Add info about the HTX structs in "show sess all" command

For HTX streams, info about the HTX structure is now dumped for the request and
the response channels in "show sess all" command.

The patch may be backported to 1.9.
diff --git a/src/stream.c b/src/stream.c
index ac323b1..8bf0917 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -3087,6 +3087,16 @@
 		             strm->txn ? strm->txn->req.next : 0, (unsigned int)ci_data(&strm->req),
 			     (unsigned int)strm->req.buf.size);
 
+		if (IS_HTX_STRM(strm)) {
+			struct htx *htx = htxbuf(&strm->req.buf);
+
+			chunk_appendf(&trash,
+				      "      htx=%p size=%u data=%u used=%u wrap=%s extra=%llu\n",
+				      htx, htx->size, htx->data, htx->used,
+				      (!htx->used || htx->tail+1 == htx->wrap) ? "NO" : "YES",
+				      (unsigned long long)htx->extra);
+		}
+
 		chunk_appendf(&trash,
 			     "  res=%p (f=0x%06x an=0x%x pipe=%d tofwd=%d total=%lld)\n"
 			     "      an_exp=%s",
@@ -3116,6 +3126,16 @@
 		             strm->txn ? strm->txn->rsp.next : 0, (unsigned int)ci_data(&strm->res),
 			     (unsigned int)strm->res.buf.size);
 
+		if (IS_HTX_STRM(strm)) {
+			struct htx *htx = htxbuf(&strm->res.buf);
+
+			chunk_appendf(&trash,
+				      "      htx=%p flags=0x%x size=%u data=%u used=%u wrap=%s extra=%llu\n",
+				      htx, htx->flags, htx->size, htx->data, htx->used,
+				      (!htx->used || htx->tail+1 == htx->wrap) ? "NO" : "YES",
+				      (unsigned long long)htx->extra);
+		}
+
 		if (ci_putchk(si_ic(si), &trash) == -1) {
 			si_rx_room_blk(si);
 			return 0;