MFC r349231, r349233, r349280, r349478

MFC r349231, r349233, r349280, r349478

r349231:
Add FIOBMAP2 ioctl

This ioctl exposes VOP_BMAP information to userland. It can be used by
programs like fragmentation analyzers and optimized cp implementations. But
I'm using it to test fusefs's VOP_BMAP implementation. The "2" in the name
distinguishes it from the similar but incompatible FIBMAP ioctls in NetBSD
and Linux.  FIOBMAP2 differs from FIBMAP in that it uses a 64-bit block
number instead of 32-bit, and it also returns runp and runb.

Reviewed by:	mckusick
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D20705

r349233:
#include <sys/types.h> from sys/filio.h

This fixes world build after r349231

Reported by:	Jenkins
MFC-With:	349231
Sponsored by:	The FreeBSD Foundation

r349280:
Reduce namespace pollution from r349233

Define __daddr_t in _types.h and use it in filio.h

Reported by:	ian, bde
Reviewed by:	ian, imp, cem
MFC-With:	349233
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D20715

r349478:
FIOBMAP2: inline vn_ioc_bmap2

Reported by:	kib
Reviewed by:	kib
MFC-With:	349238
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D20783