Use suword32 and suword64 instead of copyout(9). This fixes a bug in the
emulation of the call instruction caused by reversing the uaddr and kaddr
arguments when copying data out to userland: the suword* functions take the
uaddr as the first argument whereas copyout(9) takes the kaddr as the first
argument. This also partially undoes the fixes from r257143.

Submitted by:	Prashanth Kumar <pra_udupi@yahoo.co.in> (original version)
MFC after:	1 month
Do not coalesce if the swap object belongs to tmpfs vnode.  The
coalesce would extend the object to keep pages for the anonymous
mapping created by the process.  The pages has no relations to the
tmpfs file content which could be written into the corresponding
range, causing anonymous mapping and file content aliasing and
subsequent corruption.

Another lesser problem created by coalescing is over-accounting on the
tmpfs node destruction, since the object size is substracted from the
total count of the pages owned by the tmpfs mount.

Reported and tested by:	bdrewery
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week