- Make accelerated checksum available to InnoDB and XtraDB.
 - Fall back to slice-by-eight if not available. The mode used is printed on startup.
 - Will only build on POWER systems at the moment until CMakeLists are modified
   to only add the crc32_power8/ files when building on POWER.

running MySQL-5.7 unittest/gunit/innodb/ut0crc32-t

Before:

1..2
Using software crc32 implementation, CPU is little-endian
ok 1
Using software crc32 implementation, CPU is little-endian
    normal CRC32: real    0.148006 sec
    normal CRC32: user    0.148000 sec
    normal CRC32: sys     0.000000 sec
big endian CRC32: real    0.144293 sec
big endian CRC32: user    0.144000 sec
big endian CRC32: sys     0.000000 sec
ok 2

After:

1..2
Using POWER8 crc32 implementation, CPU is little-endian
ok 1
Using POWER8 crc32 implementation, CPU is little-endian
    normal CRC32: real    0.008097 sec
    normal CRC32: user    0.008000 sec
    normal CRC32: sys     0.000000 sec
big endian CRC32: real    0.147043 sec
big endian CRC32: user    0.144000 sec
big endian CRC32: sys     0.000000 sec
ok 2

Author CRC32 ASM code: Anton Blanchard <anton@au.ibm.com>
ref: https://github.com/antonblanchard/crc32-vpmsumSigned-off-by: Daniel Black <daniel.black@au.ibm.com>