Emitting aligned SSE movs in gcc with force_align_arg_pointer

[Daniel Santos]

I'm working on a few improvements in GCC targeting 64-bit Wine. I've got 
a patch set that gives us back aligned SSE movs for 64-bit ms_abi 
functions that call System V functions.  However, it looks like I'll 
have to wait until GCC 8's stage 1 comes around 
(https://gcc.gnu.org/ml/gcc-patches/2016-12/msg01924.html), but I 
thought I should post this here to prevent any duplication of effort.  
(Come to think of it, I should probably open a gcc bug report for 
this.)  Following this patch set I have the out-of-lining patch set for 
the msabi/sysv prologues & epilogues as well that I'm still refining and 
cleaning up a bit.

Happy New Year all!

Daniel