lua: dostring alias + diagnosis notes; keep grinding scoreboard

lib/lua/runtime.sx

@@ -1491,6 +1491,8 @@
 (define loadstring lua-loadstring)
 (define load lua-loadstring)
 
+(define dostring (fn (s) (let ((f (lua-loadstring s))) (f))))
+
 ;; select(n, ...) — Lua 5.1 built-in. select("#", ...) is arg count; select(i, ...) returns args from i on.
 (define
   lua-select