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

Stop hard-coding a 32-bit data model for USDT tests, and just use the native
model. This was causing many of the tests to fail on amd64 since USDT
support for 32-bit programs is currently non-functional.

MFC after: 1 week

Stop hard-coding an incorrect path to rm(1).

MFC after: 1 week

Remove hard-coded invocations of gcc; use cc(1) instead.

MFC after: 1 week

Dtrace: enablings on defunct providers prevent providers from unregistering

Merge change from illumos:

1368 enablings on defunct providers prevent providers from unregistering

We try to address some underlying differences between the Solaris
and FreeBSD implementations: dtrace_attach() / dtrace_detach() are
currently unimplemented in FreeBSD but the new code from illumos
makes use of taskq so some adaptations were made to dtrace_open()
and dtrace_close() to handle them appropriately.

Illumos Revision: r13430:8e6add739e38

Reference:
https://www.illumos.org/issues/1368

Reviewed by: gnn
Tested by: Fabian Keil
Obtained from: Illumos
MFC after: 3 weeks

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