Compilation of LAPACKE possibly independent from Fortran

[weslleyspereira]

Attempt to close #273.

#273 has an interesting idea in my view. If one needs only LAPACKE (for instance, if LAPACK is already installed), Fortran compiler may not be necessary. This PR is my first step towards this idea.

Still needs testing, so I am putting this as a Draft.

[codecov]

Codecov Report

Attention: 413 lines in your changes are missing coverage. Please review.

Comparison is base (02ea2d3) 0.00% compared to head (3a86ff7) 0.00%.
Report is 3 commits behind head on master.

❗ Current head 3a86ff7 differs from pull request most recent head bf50aff. Consider uploading reports for the commit bf50aff to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #834   +/-   ##
=======================================
  Coverage    0.00%    0.00%           
=======================================
  Files        1918     1918           
  Lines      188642   188645    +3     
=======================================
- Misses     188642   188645    +3     

Files	Coverage Δ
SRC/chseqr.f	0.00% <ø> (ø)
SRC/cggglm.f	0.00% <0.00%> (ø)
SRC/cgglse.f	0.00% <0.00%> (ø)
SRC/cggqrf.f	0.00% <0.00%> (ø)
SRC/cggrqf.f	0.00% <0.00%> (ø)
SRC/chesv_aa_2stage.f	0.00% <0.00%> (ø)
SRC/chetrs_aa.f	0.00% <0.00%> (ø)
SRC/csysv_aa_2stage.f	0.00% <0.00%> (ø)
SRC/csytrf_aa_2stage.f	0.00% <0.00%> (ø)
SRC/csytrs_aa.f	0.00% <0.00%> (ø)
... and 203 more

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[weslleyspereira]

Rebased with current master.

[weslleyspereira]

I put a test in the CI, so it should be now good to merge

[drhpc]

Oh, in #972 I added fixed Fortran language use in order to introduce optional C++ use. Might want to adapt that to fix both issues properly. My gripe was that suddenly CMake requires a working C++ compiler even without LAPACK++ or BLAS++. The pkgsrc build environment is picky and only provides the compilers a package claims to need.