Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.Approved by: re (implicit)Sponsored by: The FreeBSD Foundation
Avoid accidental conflicts with C++ operator keywords.MFC after: 1 week
style(9): tab after #define.
$Id$ -> $FreeBSD$
Fixed garbage after comment after #endif. Fixed reversed sense of samecomment.
Added iso646.h as defined by the Single UNIX Specification, version 2.