FreeBSD_HEAD_arm64 - Build #2385 - Fixed

[jenkins-admin at FreeBSD.org]

FreeBSD_HEAD_arm64 - Build #2385 - Fixed:

Build information: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_arm64/2385/
Full change log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_arm64/2385/changes
Full build log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_arm64/2385/console

Change summaries:

295762 by zbb:
Fix build for i386 and arm64 after r295755

- Take bus_space_tag_t type into consideration when returning
  default, zero value.
- Include missing rman.h required by ofw_pci.h

295761 by br:
Increase kernel and user VA space.
This allows us to boot with more than 128MB of physical memory.

Sponsored by:	DARPA, AFRL
Sponsored by:	HEIF5

295760 by se:
Make WARNS=6 safe.

Tested with Clang 3.7.1, GCC 4.2.1 and GCC 4.8.5 on amd64.

295759 by imp:
Remove a stray else. It isn't needed (due to the return at the end of
the if statement it pairs with). While not an error today, a careless
edit in the future could cause problems (though given the nature of
this specific code, the problems quite likely would be some variation
of "most direct access SCSI storage devices won't attach," which is
unlikely to go unnoticed).

PVS-Studio: V705

295758 by br:
Use medany (Medium/Anywhere) GCC code model for RISC-V.
This will allow us to use bigger relocations and all
the 64-bit VA space.

295757 by emaste:
Remove dd xfer stats emitted during buildworld

They result in gratuitous differences when comparing build log output.