[jhc] Optimization.

Greetings, The attached patch is a two-step optimization: 1) Only call 'getType' 100,000,000 times instead of 600,000,000 times. 2) Greatly simplify the actual loop. Without this patch, compiling base-1.0.hl takes 19 minutes. With this patch, compile time is down to 11 minutes. Feedback would be greatly appreciated. -- Cheers, Lemmih