dtrace: add support for sparc64 1of3

dtrace: add support for sparc64 1of3

This commit is the 1st of 3 commits to add DTrace support to the sparc64
kernel.  This particular commit covers the sparc64-specific kernel code
changes.

- Set ARCH_SUPPORTS_DTRACE for SPARC64.

- Add DIE_PAGE_FAULT to be used in the (new) notifier call in the
  do_kernel_fault() function to allow DTrace to report failed memory
  accesses from probe recipes as an error rather than causing a kernel
  OOPS.

- Add support for the dtrace_no_pf() functionality to ignore page faults
  on request when trying to access userspace.

- Add support for the waitfd syscall.

Orabug: 19005031

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>