Fix a couple of issues in the PUSH emulation:

It is not possible to PUSH a 32-bit operand on the stack in 64-bit mode. The
default operand size for PUSH is 64-bits and the operand size override prefix
changes that to 16-bits.

vm_copy_setup() can return '1' if it encounters a fault when walking the
guest page tables. This is a guest issue and is now handled properly by
resuming the guest to handle the fault.
Fix typo.

MFC after:	3 days
Fix structure of new tests (r268794) for usr.bin/units.

- Make sure the tests go into the right directory.  The location was
  wrong so they were overwriting the bin/chown tests!
- Use the right naming scheme for the test program.
- Remove the svn:executable property from the shell script.
As of r268075, the responsibility of rounding up buffer to optimal size have
been transferred from zio_compress_data to its caller.  Therefore, passing
the 'minblocksize' down will be a no-op.

Eliminate the parameter to reduce diff against upstream.

MFC after:	2 weeks