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: re-apply r249426 now that the underlying issues have been solved.

Merge change from illumos:

3519 DTrace fails to resolve const types from fbt
3520 dtrace internal error -- token type 316 is not a valid D
compilation token
3521 clean up dtrace unit tests

Illumos Revision: e98f46c

Reference:
https://www.illumos.org/issues/3519
https://www.illumos.org/issues/3520
https://www.illumos.org/issues/3521

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

Dtrace: resolve const types from fbt and other fixes.

Merge change from illumos:

3519 DTrace fails to resolve const types from fbt
3520 dtrace internal error -- token type 316 is not a valid D
compilation token
3521 clean up dtrace unit tests

Illumos Revision: e98f46c

Reference:
https://www.illumos.org/issues/3519
https://www.illumos.org/issues/3520
https://www.illumos.org/issues/3521

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

Update vendor/illumos/dist to illumos-gate version 13944:bbcbb468dc37

Illumos dtrace issues:
3519 DTrace fails to resolve const types from fbt
3520 dtrace internal error -- token type 316 is not a valid D compilation token
3521 clean up dtrace unit tests