Suggestion: a global hash cache

There is a "lineCache" in official text plugin, which provided alloc/free method to decrease the GC of hash table.

My suggestion is , the engine (cr) might provide a global "lineCache" (a single, global "hash table cache") for any plugin which need alloc/free hash table frequently.

Javascript engines perform best when objects have a consistent shape (i.e. the same properties). If we shared objects between unrelated plugins which used different shape objects, that could actually reduce performance. It seems better to make a separate recycling cache for each shape of object, since you get both GC recycling and high performance. Still, perhaps we could have written a library to make this easier...