optimize

[HEIHUAa]

Since the last code optimization, I've been making changes here and there, and now it's time to summarize them.

Optimized operations like x += 1: previously they would allocate a closure (creating a temporary function) and x would require two variable lookups. Now it's directly cached, no closure allocation is needed, and it's about 35% faster.

Previously, in for (i in 0...10), a variable object was recreated after each loop iteration. Now it's reused.

Optimized reading engine object fields: previously it had to check twice whether it was a special script object each time. Now the result is cached directly, improving speed by about 16%.

Optimized creating many instances of the same object with new: specifically, instead of doing a table lookup every time, the result is now cached. Creating the same object 10,000 times is about 20% faster.

Improved the speed of reading fields that are originally null, such as FlxG.save.data.xxx, by about 15% (only for hscriptPos).

Previously, function parameter declarations + loop variables + locals would all create a new internal record object. Now they are reused.

Merged the two sets of code for assign/evalAssignOp to remove duplication.