Suppress -Wunused-but-set-variable on variable (#4777)
sentinel_count is not used in non-assert builds.
Recent clang improvements to -Wunused-but-set-variable trigger a warning on this.
Fixes #4772.
diff --git a/source/util/ilist.h b/source/util/ilist.h
index b7ecf01..42d5e62 100644
--- a/source/util/ilist.h
+++ b/source/util/ilist.h
@@ -348,6 +348,7 @@
p = p->next_node_;
} while (p != start);
assert(sentinel_count == 1 && "List should have exactly 1 sentinel node.");
+ (void)sentinel_count;
p = start;
do {
