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

Hook up support for userland CTF support in DTrace. This required some
modifications to libproc to support fetching the CTF info for a given file.

With this change, dtrace(1) is able to resolve type info for function and
USDT probe arguments, and function return values. In particular, the args[n]
syntax should now work for referencing arguments of userland probes,
provided that the requisite CTF info is available.

The uctf tests pass if the test programs are compiled with CTF info. The
current infrastructure around the DTrace test suite doesn't support this
yet.

Differential Revision: https://reviews.freebsd.org/D891
MFC after: 1 month
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division

Fix elfdump(1) usage in the userland CTF tests.

PR: 193110
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

MFV illumos

4474 DTrace Userland CTF Support
4475 DTrace userland Keyword
4476 DTrace tests should be better citizens
4479 pid provider types
4480 dof emulation is missing checks

MFC after: 2 weeks

4474 DTrace Userland CTF Support
4475 DTrace userland Keyword
4476 DTrace tests should be better citizens
4479 pid provider types
4480 dof emulation is missing checks

illumos/illumos-gate@a386cc11a86ecb60f5a48078d22c1500e2ad003e