- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r258800, r258802, r258805, r258806, r258807, r258851, r258857,
r259199, r259484, r259513, r259514, r259516

The kernel stack guard pages are only below the stack pointer, not above.

Remove unnecessary double-setting of the thread's onfault state in
copyinstr().

Open Firmware mandates that certain cross-references, in particular those
in /chosen, be ihandles. The ePAPR spec makes those cross-reference phandles,
since FDT has no concept of ihandles. Have the OF FDT CI module interpret
queries about ihandles as cross-reference phandles.

Real OF systems have an ihandle under /chosen/stdout, not a phandle. Use
the right type.

Rearchitect platform memory map parsing to make it less
Open Firmware-centric.

Remove fdtbus_bs_tag definition, which is now obsolete. The remainder of
this file is also slated for future demolition.

Return the correct IEEE 1275 code for "nextprop".

Use the common Open Firmware PCI interrupt routing code instead of the
duplicate version in dev/fdt.

Configure interrupt sense based on device tree information.

Simplify the ofw_bus_lookup_imap() API slightly: make it allocate maskbuf
internally instead of requiring the caller to allocate it.

MFC r257162, r257175

The old trap.h (then trap_aim.h) actually had trap ID codes for Book-E CPUs.
Use it universally. Book-E traps may also need revisiting due to the
introduction of fixed-offset traps and the deprecation of IVORs in POWER
ISA 2.06, but that's very much an issue for another day.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Rework handling of ofw_quiesce(), making it the responsibility of the
platform modules. Whether to call this function or not is highly machine
dependent: on some systems, it is required, while on others it breaks
everything. Platform modules are in a better position to figure this
out. This is required for POWER hypervisor SCSI to work correctly. There
are no functional changes on Powermac systems.

Approved by: re (kib)

As idling the CPU no longer causes hangs on QEMU, reenable the pSeries
cpu_idle() routine.

Approved by: re (delphij)

Merge in support for PAPR-compliant (Power Architecture Platform
Requirements) systems from the projects/pseries branch. This in principle
includes all IBM POWER hardware released in the last 15 years with the
exception of POWER3-based systems when run in 64-bit mode. The main
development target, however, has been the PAPR logical partition support
that is the default target in KVM on POWER and QEMU -- mileage may vary
on actual hardware at present. Much of the heavy lifting here was done
by Andreas Tobler.

Approved by: re (kib)