Add a /* fall through */ comment

load.c

@@ -923,6 +923,7 @@ search_required(VALUE fname, volatile VALUE *path, int safe_level, feature_func
 	    if (loading) *path = rb_filesystem_str_new_cstr(loading);
 	    return ft;
 	}
+        /* fall through */
       case 1:
 	ext = strrchr(ftptr = RSTRING_PTR(tmp), '.');
 	if (rb_feature_p(ftptr, ext, !--type, TRUE, &loading) && !loading)