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

- While SPARC V9 allows tininess to be detected either before or after
rounding (impl. dep. #55), the SPARC JPS1 responsible for SPARC64 and
UltraSPARC processors defines that in all cases tinyness is detected
before rounding, therefore rounding up to the smallest normalised
number should set the underflow flag.
- If an infinite result is rounded down, the result should have an
exponent 1 less than the value for infinity.

PR: 144900
Submitted by: Peter Jeremy
MFC after: 3 days

FPU_DEBUG requires <stdio.h>.

PR: 144900
Submitted by: Peter Jeremy
MFC after: 3 days

Ensure that __fpu_ftox() both returns the high bits and res[1] contains
the low bits also in the default case.

PR: 144900
Obtained from: OpenBSD
MFC after: 3 days

- Remove a bogus forward declaration.
- Fix whitespace.

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Fix a typo in __fpu_ftox() that caused long double to long (and long long)
conversion of negative numbers to always result in -1.
While at it, rearrange the nearby comment so it fits in 80 chars per line,
like the rest of this file does.

PR: 107130
MFC after: 1 day

s/round/fpround/ to avoid naming clash with GCC builtin function.

Emulate ldq and stq (load/store long double) instructions. GCC has started
using these to load long doubles, but they aren't implemented in hardware
on (at least) UltraSPARC I and II machines.
Emulate popc in the user trap handler as well.
Re-arrange slightly to make support functions more accessible.

Reviewed by: tmm

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove __P() usage.

Remove 'register' keyword.

Add userland floating point emulator code for sparc64. This is a port
of the (never committed) in-kernel version (with some optimizations and
cleanups), which in turn was ported from NetBSD.