Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Replace a proliferation of buggy MD implementations of modf() with a
working MI one. The MI one only needs to be overridden on machines
with non-IEEE754 arithmetic. (The last supported one was the VAX.)
It can also be overridden if someone comes up with a faster one that
actually passes the regression tests -- but this is harder than it sounds.

Fix whitespace inconsistencies found in homegrown Symbol.maps.

Merge jmallett@'s n64 work into HEAD - changeset 2

Update libc Makefiles.
Add makecontext implementation.

Changes from http://svn.freebsd.org/base/user/jmallett/octeon

Approved by: rrs(mentor), jmallett

Merge r195030 from project/mips to head by hand

r195030 | gonzo | 2009-06-25 19:27:31 -0600 (Thu, 25 Jun 2009) | 4 lines
- Switch to libc softfloat from libgcc implementation. The problem
with latter is that it is not complete, fpsetXXX/fpgetXXX
functions are missing.

Merge r197800 from projects/mips to head by hand:

r197800 | gonzo | 2009-10-06 00:35:52 -0600 (Tue, 06 Oct 2009) | 3 lines
- curbrk variable for sbrk and brk should be the same
- Add correct variable names to Symbol.map

These symbols don't belong here. Remove them. Since mips hasn't had
a release, I think there's no impact here...

Reviewed by: cognet@

Add mips support libc from the mips2-jnpr branch of perforce.