crc32c: add intel baseline algorithm

This is than the sctp code but probably slower.  We'll add it anywhere
just as a reference and to have a baseline for comparing performance.

Signed-off-by: Sage Weil <sage@inktank.com>
crc32c: note intel crc code copyrights

It's a BSD 3-clause.

Signed-off-by: Sage Weil <sage@inktank.com>
crc32c: add intel sse4.2 detection

Signed-off-by: Sage Weil <sage@inktank.com>
build-depend on yasm

Signed-off-by: Sage Weil <sage@inktank.com>
yasm-wrapper: hide libtool insanity from yasm

libtool passes all kinds of crap to yasm that yasm does not understand.
Hide it with this ugly wrapper.  Sigh.

Signed-off-by: Sage Weil <sage@inktank.com>
crc32c: add optimized intel crc32c implementation

This is from Intel's ISA-L library and licensed under BSD 3-clause.

Signed-off-by: Sage Weil <sage@inktank.com>
arch: move cpu probing to arch/

Keep this seperate from the crc32c code.

Signed-off-by: Sage Weil <sage@inktank.com>