some fixes for virtual hosting support from Rajeev V. Pillai:

- memory leaks in virtual host plugged
- ensure hr_host is only the host/port part when the request
  contains the hostname in the URI not Host: header.


also update the references to the old http/1.1 draft rev 06
to RFC 2616 (fortunately, most sections hadn't moved.)
Remove a few noisy debug printf.
- bump man page date
- strip :80 off virtual host names as they're the default
Revert previous revision. It bkeaks profiling kernel builds.
LIBISPRIVATE unconditionnally set MKPROFILE to no, preventing
profiling kernel library.
Fix error message; argv[1] could be NULL
Update for atf 0.19.
Add compatibility for some userspace code (eg firefox) that seems to look
  inside the ucontext structure passed to signal handlers to modify the
  xmm registers.
This should make the code compile - I'm not at all sure it works as expected,
  the interactions between FP and signal handlers aren't at all clear.
AFAICT the FP state is saved on the user stack when the handler is called,
  however the FP trap code can already done odd things to the FPU....
Reorder code to avoid using an uninitialized variable: if
sysctl_copyin fails, 'tmp' is not initialized. This bug is
harmless since only the return value will be different;
it does not expose kernel memory unless diagnostic is enabled.

ok agc@ martin@
account for the 16 bytes of AT_RANDOM data in the stack setup.  fixes PR 48518.
use cprng_strong32() instead of random().  add AT_RANDOM support for linux32.
Add x86_stmxcsr for amd64.
When layer_node_alloc() finds another thread already inserted the node
into the hashlist and discards the now unneeded node it will raise a
panic "dead but not clean".

Reorder the initialization and use ungetnewvnode() to discard the node.
Adjust comment and change vput() to vrele().  This change got missed
when changing vnode creation operations to return unlocked result.
Best if x86_stmxcsr executes stmxcsr.
Use compiler builtins instead of atf_arch and atf_machine.

The atf_arch and atf_machine configuration variables were removed from
atf-0.19 without me realizing that some tests were querying them directly.

Instead of reintroducing those variables, just rely on compiler builtins
as many other tests already do.

Should fix PR bin/48582.
Simplify fputrap() considerably.
There is no need to save the fpu state here, and definitely no need
  to initialise the fpu.
The code is running with interrupts disabled having trapped on either
  an x87 instruction (the one after the one that generated the error)
  or on an SSE (etc) instruction that caused the error.
So all it needs to do it obtain the 'error' bits from the relevant
  status register, clear the bits, and then raise any signal.
The signal code will save the fp state if the signal itself isn't masked.
It also passes the FP state to the signal handler - which can modify it.
(I suspect that wasn't thecase when this code was written.)
Seems to work for both 64bit and 32bit 'divide by zero' errors.
For the xmm trap, the xmm registers are updated for the result of the
  instruction, but the trap returns to re-execute the instruction!
This makes it difficult for the signal handler to do anything sensible.

I've also changed the code to only use unmasked error bits when deciding
the signal code.
Tidy up and correct some comments.
Replace the hand generated 28 lines that initialised fpetable[]
  with some pre-processor expressions.
The latter was verified to give the same table entries.
Steal the table from i386/isa/npx.c than selects the highest priority
  floating point error when raising a signal.
Multiple errors bits can easily be set if different sub-fields of an
xmm simd operation generate different errors.
in update_db(), extract the full list of files to update from the db
before actually updating anything, since changing the db while the query
that extracts the list of files is still in progress results in
the extraction query failing before it finds everything.
add myself
Move the "-U or -E must be set for build as an unprivileged user."
test from sanitycheck() to validatemakeparams().  If MKUNPRIVED is set
in mk.conf (and not on the build.sh command line) then it's not yet
available for use in the sanitycheck function.

Also move some other code for consistency.