[patch] Remove the reg2mem pass

[Rafael Espíndola]

> I suppose that'll make
> http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130916/188302.html
> redundant?

Thanks for the pointer. I will reply to that thread to see if they are
still using it.

> Could you mention what replaces the functionality? I vaguely remember it was
> useful for working with IR but that was a long time ago :-)
>
> Anyway, don't forget to update the reg2mem documentation in Passes.rst if
> you remove this.
>
> Alp.

Thanks,
Rafael