Fix warning
../../src/hb-ot-layout-gsubgpos-private.hh:391:18: warning: missed loop optimization, the loop counter may overflow [-Wunsafe-loop-optimizations]
diff --git a/src/hb-ot-layout-gsubgpos-private.hh b/src/hb-ot-layout-gsubgpos-private.hh
index 661085d..cbaa648 100644
--- a/src/hb-ot-layout-gsubgpos-private.hh
+++ b/src/hb-ot-layout-gsubgpos-private.hh
@@ -388,7 +388,7 @@
inline bool prev (void)
{
assert (num_items > 0);
- while (idx >= num_items)
+ while (idx > num_items - 1)
{
idx--;
const hb_glyph_info_t &info = c->buffer->out_info[idx];