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

Replace use of ${.CURDIR} by ${LIBC_SRCTOP} and define ${LIBC_SRCTOP}
if not already defined. This allows building libc from outside of
lib/libc using a reach-over makefile.

A typical use-case is to build a standard ILP32 version and a COMPAT32
version in a single iteration by building the COMPAT32 version using a
reach-over makefile.

Obtained from: Juniper Networks, Inc.

Merge in the latest SoftFloat changes from NetBSD. (NetBSD isn't the
original vendor, but we're using their heavily modified version.)
This brings in functions for long double emulation (both extended and
quad formats), which may be useful for testing, and also for replacing
libc/sparc64/fpu/.

Powerpc is special here. powerpc and powerpc64 use different ABIs, so
their implementations aren't in the same files. Introduce LIBC_ARCH
and use that in preference to MACHINE_CPUARCH. Tested by amd64 and
powerpc64 builds (thanks nathanw@)

MFtbemd:

Prefer MACHNE_CPUARCH to MACHINE_ARCH in most contexts where you want
to test of all the CPUs of a given family conform.

Add each directory's symbol map file to SYM_MAPS.

Remove fpsetsticky(). This was added for SysV compatibility, but due
to mistakes from day 1, it has always had semantics inconsistent with
SVR4 and its successors. In particular, given argument M:

- On Solaris and FreeBSD/{alpha,sparc64}, it clobbers the old flags
and *sets* the new flag word to M. (NetBSD, too?)
- On FreeBSD/{amd64,i386}, it *clears* the flags that are specified in M
and leaves the remaining flags unchanged (modulo a small bug on amd64.)
- On FreeBSD/ia64, it is not implemented.

There is no way to fix fpsetsticky() to DTRT for both old FreeBSD apps
and apps ported from other operating systems, so the best approach
seems to be to kill the function and fix any apps that break. I
couldn't find any ports that use it, and any such ports would already
be broken on FreeBSD/ia64 and Linux anyway.

By the way, the routine has always been undocumented in FreeBSD,
except for an MLINK to a manpage that doesn't describe it. This
manpage has stated since 5.3-RELEASE that the functions it describes
are deprecated, so that must mean that functions that it is *supposed*
to describe but doesn't are even *more* deprecated. ;-)

Note that fpresetsticky() has been retained on FreeBSD/i386. As far
as I can tell, no other operating systems or ports of FreeBSD
implement it, so there's nothing for it to be inconsistent with.

PR: 75862
Suggested by: bde

Import the softfloat emulation library, needed for FreeBSD/arm right now.
It should become useless when gcc 3.4 will be imported, as libgcc from
gcc 3.4 contains this bits for arm.