RFR: src:lapack's 64bit-indexing variant

[Mo Zhou <lumin@debian.org>]

Hi science team,

My 64bit-indexing updates for src:lapack are ready for
review. Please have a look at my git commits on the
"lumin" branch:

  git@salsa.debian.org:science-team/lapack.git -b lumin

Several points to note:

1. I merged the content of liblapack-pic into
   liblapack-dev.

2. Upstream CBLAS code is not ready for the
   64bit-indexing feature. the upstream somehow postponed
   this feature[1]. As a result, I didn't deal with
   the CBLAS build and CBLAS development files.
   I can patch CBLAS, but let's do it when the
   64bit variant of OpenBLAS is available.

3. the test packages and autopkgtest updates are
   postponed by me. Let's finalize them in the
   next round of src:lapack update with the
   CBLAS64 patch.

[1] https://github.com/Reference-LAPACK/lapack/issues/184