Basically just copied all the amd64 files, removed all the *Q ops,
and rebuilt.

Compiles fib successfully.

Still need to do:
 - all the 64->32 bit op translations.
 - audit for instructions that aren't available on 386.
 - GO386=387?

Update #16358

Change-Id: Ib8c684586416a554a527a5eefa0cff71424e36f5
Reviewed-on: https://go-review.googlesource.com/24912Reviewed-by: Cherry Zhang <cherryyz@google.com>