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
with r265456 _r_debug_postinit can be used for RD_POSTINIT events. rtld(1)
uses r_debug_state for dl state transitions, so we use its address for
RD_DLACTIVITY events.
MFC after: 2 weeks
