sparc64 crc32c opcode not available

[Chris Ross <cross+debian@distal.com>]

Hey.  I have my T5120 running, recently updated packages including kernel
(4.16.0-1-sparc64-smp).  On the system's console I'm seeing two messages
of concern, periodically:

[27482.619730] Kernel unaligned access at TPC[120bc270] sa_build_layouts+0x5f0/0x8c0 [zfs]

and

[18307.649038] crc32c_sparc64: sparc64 crc32c opcode not available.

The former I'll need to ask the zfs-linux folks about, but let me know if you
already know anything about it.

The second is the real question for this list.  Is this something you've seen
before?  Is it indicative of a real problem, or just noisy notification of
something that causes no real problem?

                 - Chris