The bulk of this patch is the new win64.asm, which is a more-or-less
direct copy of aarch64's sysv.S file, with modifications for armasm64's
peculiarities. The changes to ffi.c were minimal, mostly so that
arithmetic on `void*` conforms to the C standard.
In bug 1296530, we made @depends take a when argument, it can now replace
all uses of @depends_when.
--HG--
extra : rebase_source : d090723fcbf3a56e06bd9c2defc3301cac04d8b0
Mike Hommey
Nathan Froyd
Chris Manchester