Details:
The basic idea is inverse of singular matrix doesn't exist,
therefore we should be returning NAN. BLAS standard and BLIS
is optimizing by not doing any compute when x[j]== 0. As a
result BLIS is generating finite values for inverse
calculation of singular matrices which in reality is not
the right answer. Fix is provided in this commit to generate
NAN/INF values incase this API is called to compute inverses
of singular matrices. But according to the standard, this API
shouldn't be called in the first place, the check for singularity
or near singularity should be done by the calling application
Change-Id: Iccdbc07744de3892626f4066ee4a63eb30bc06cd
40e1fd1860