Thumb2 code size improvements

[Yao Qi]

Loïc Minier wrote:
>  I see you moved the wiki page to the public space, thanks
> 
>  Couple of notes:
>  * make sure you use the rename action on the page, I think this will
>    preserver history (I didn't check whether you did or not, but I think
>    not)

No, I didn't.  I use copy and paste.  I'll use rename action.

>  * add a page at the old location with "#redirect NewPage" or
>    "#refresh 0 http://newurl/"

OK, got it.  Thanks for your help on wiki.