BLD: Fixed detection for recent MKL versions

[xabellan]

The detection of the MKL library was broken. According to Intel, the recommended way to build numpy and use MKL is to define a site.cfg with the values:

library_dirs = /opt/intel/compilers_and_libraries_2016/linux/mkl/lib/intel64
include_dirs = /opt/intel/compilers_and_libraries_2016/linux/mkl/include
mkl_libs = mkl_rt
lapack_libs = 

See https://software.intel.com/en-us/articles/numpyscipy-with-intel-mkl for more info.

The name of the libraries in system_info has been updated so now no site.cfg is needed if the MKLROOT environment variable is properly set to detect MKL.

[charris]

What is the reason for removing this? If the class is empty, a remark explaining why would be helpful.

[charris]

Any reason to leave the class rather than remove it completely?

[xabellan]

I left it empty for consistency with the other mkl_info subclass blas_mkl_info, which was also empty. I guess you could remove both and just use the parent mkl_info class for both blas_mkl and lapack_mkl in the cl dictionary.

[charris]

Does this work for older MKL also?

[charris]

lapack_libs = seems a bit odd.

[charris]

See also #7717.

[xabellan]

It should work from MKL version 13 onwards. I tested on 13, 14, 15 and 16, which are the ones I have access to.

I also changed the is_Xeon check because it was not picking up the intel core i* family as 64 bit. I replaced it by a generic check for intel and 64 bit platform.

[charris]

Well, let's give it a shot. Thanks @xabellan .