Using VFP registers in the msun fenv functions

[Andrew Turner]

I'm working on merging in my hard-float changes into head. As part of
this I have updated msun to use both the softfloat and, when available,
the vfp environment.

I've done minimal testing, i.e. compiling and running a simple rootfs
with it. I would appreciate it if people with more knowledge in this
area could check over the patch, and try to run it against any
floating-point code they have to check it still works as expected.

The patch is available from [1]

Andrew

[1] http://people.freebsd.org/~andrew/armv6fenv2.diff