MFC r305334: MFV r304157:

MFC r305334: MFV r304157:
7230 add assertions to dmu_send_impl() to verify that stream includes BEGIN and
END records

illumos/illumos-gate@12b90ee2d3b10689fc45f4930d2392f5fe1d9cfa
https://github.com/illumos/illumos-gate/commit/12b90ee2d3b10689fc45f4930d2392f5f
e1d9cfa

https://www.illumos.org/issues/7230
  A test failure occurred where a send stream had only a BEGIN record. This
  should not be possible if the send returns without error. Prevented this from
  happening in the future by adding an assertion to dmu_send_impl() to verify
  that if the function returns 0 (success) both a BEGIN and END record are
  present. Did this by adding flags to dmu_sendarg_t (indicating whether BEGIN o
r
  END records sent), having dump_record() set flags appropriately, adding VERIFY
  statement to dmu_send_impl().

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matt Krantz <matt.krantz@delphix.com>

git-svn-id: svn://svn.freebsd.org/base/stable/10@307285 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f