Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Dtrace: add optional size argument to tracemem().

Merge change from illumos:

1455 DTrace tracemem() should take an optional size argument

Our local enhancements to dt_print_bytes were equivalent to
those in illumos but we made it match the illumos version
to ease further code merges.

For now leave out tst.smallsize.d and tst.smallsize.d.out
since those don't seem to work cleanly on FreeBSD.

This change bumps the DT_VERS_* number to 1.7.1 in accordance
to what is done in illumos.

Illumos Revision: 13457:571b0355c2e3

Reference:
https://www.illumos.org/issues/1455

Tested by: Fabian Keil
Obtained from: Illumos
MFC after: 1 month

Update vendor/illumos/dist to pre libzfs_core state (dtrace and ctf part)
illumos-gate revision 13742:b6bbdd77139c

Obtained from: ssh://anonhg@hg.illumos.org/illumos-gate