Do not set 'flush to zero' VFPSCR_FZ bit by default. The correct
implementation of IEEE 754 arithmetic depends on denormals operating
correctly. Both perl test suite and paranoia tripped over the
setting.

Reported by: Stefan Parvu <sparvu@kronometrix.org>
Discussed with: andrew
Sponsored by: The FreeBSD Foundation
MFC after: 1 week