[Bug target/116509] 128bit integer compares can be improved

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116509

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 62607
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62607&action=edit
current patch except for movcc

This my current patch except for movcc support.

There is also a few other things missing optimizations:
* sbcs uses a temp register instead of xzr as the output.

But it seems to work for cbranch and cset. and even movcc with SImode; I didn't
test DImode. TI mode conditional move is not working.