MFC: r247579

- Move reporting of failures to disable RX/TX MAC under bootverbose as at
  least the Saturn chips of 501-6738 cards may fail to do so the first
  time, which isn't fatal though.
  Reported by: Paul Keusemann
- Explain why we don't enable infinite bursts on sparc64.
- Given that these chips support memory write invalidate, make sure that
  it's enabled in the command register. Also make sure that PERR# and
  SERR# assertion is enabled.
MFC: r247600, r247620

- While Netra X1 generally show no ill effects when registering a power
  fail interrupt handler, there seems to be either a broken batch of them
  or a tendency to develop a defect which causes this interrupt to fire
  inadvertedly. Given that apart from this problem these machines work
  just fine, add a tunable allowing the setup of the power fail interrupt
  to be disabled.
  While at it, remove the DEBUGGER_ON_POWERFAIL compile time option and
  make that behavior also selectable via the newly added tunable.
- Correct an incorrect argument to shutdown_nice(9).
- Mark unused parameters as such.
- Use NULL instead of 0 for pointers.
MFC: r247601, r247621

- Correct an incorrect argument to shutdown_nice(9).
- Mark unused parameters as such.
- Use NULL instead of 0 for pointers.
MFC: r247632

- Complete r231621 (MFC'ed to stable/9 in r232092) by also blacklisting the
  bridge used by VMware for PCIe devices. While at it, update the comment
  now that we know that MSI-X doesn't work with ESXi 5.1 for Intel 82576
  either and the underlying issue is a bug in the MSI-X allocation code of
  the hypervisor.
  Reported by: Harald Schmalzbauer
- Make the nomatch table const.