erasure-code: SSE optimized jerasure plugins

The jerasure plugin is compiled with three sets of flags:

* jerasure_generic with no SSE optimization
* jerasure_sse3 with SSE2, SSE3 and SSSE3 optimizations
* jerasure_sse4 with SSE2, SSE3, SSSE3, SSE41, SSE42 and PCLMUL optimizations

The jerasure plugin loads the appropriate plugin depending on the CPU
features detected at runtime.

http://tracker.ceph.com/issues/7826 fixes #7826

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: increase osd verbosity during functional tests

Signed-off-by: Loic Dachary <loic@dachary.org>
erasure-code: test jerasure SSE optimized plugins selection

Test the selection of the plugin depending on the CPU features. The
prefix of the plugin is "jerasure" by default (jerasure_generic,
jerasure_sse3, jerasure_sse4) and can be modified with the
"jerasure-name" parameter. A test plugin is created for each
variant (test_jerasure_generic, test_jerasure_sse3, test_jerasure_sse4).
The flags set by ceph_probe are modified by the test to check if the
expected plugin suffix is appended.

Signed-off-by: Loic Dachary <loic@dachary.org>
erasure-code: test encode/decode of SSE optimized jerasure plugins

If the machine running make check has the required CPU features
available, load the SSE optimized plugin and check that it can encode /
decode a simple payload. If the CPU features are not available, only
test the generic plugin and display an informative message about the
tests that were skipped.

Signed-off-by: Loic Dachary <loic@dachary.org>