- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Use a spin lock instead of a mutex to gate RTAS. This is required if RTAS
calls are involved in interrupt handling.

Approved by: re (kib)

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

Add better error handling for RTAS calls. These can potentially cause
machine checks (e.g. invalid PCI configuration cycles), but these can
be caught and recovered from. This change also the RTAS PCI driver to
work without modification as a replacement for the Grackle driver on
Grackle-based Powermacs.

MFpseries:
Renovate and improve the AIM Open Firmware support:
- Add RTAS (Run-Time Abstraction Services) support, found on all IBM systems
and some Apple ones
- Improve support for 32-bit real mode Open Firmware systems
- Pull some more OF bits over from the AIM directory
- Fix memory detection on IBM LPARs and systems with more than one /memory
node (by andreast@)