This reverts commit 9b24b31419.

It turns out that PRs 4515 and 4520 break the tests under
lapack-netlib/TESTING which require SECOND and DSECND. IBM
has decided this is a bigger biger problem than the conflict
between lapack second_ and the xlf run time.

* Move ?GELQS and ?GEQRS from TESTING/LIN to DEPRECATED (Reference-LAPACK PR 900)

* Add f2c-converted versions of ?GELQS and ?GEQRS

* Add C equivalents of the Fortran routines from Reference-LAPACK as fallbacks, and C_LAPACK variable to trigger their use

* Update make.inc entries for LAPACK 3.9.0

Reference-LAPACK PR 347 changed some variable names and relative paths

* Update LAPACK to 3.9.0

* Add new functions from LAPACK 3.9.0

* Add new functions from LAPACK 3.9.0

* Restore LOADER command 

as it makes it easier to specify pthread as needed

* Restore LOADER

* Restore EIG/LIN prefixes in cmdbase

* add binary path to lapack_testing.py call

* Restore OpenMP version check

* Restore OpenMP version check

* Restore fix for out-of-bounds array accesses

from #2096

The problem is that OpenBLAS sets the LAPACKE_LIB and the TMGLIB to the
same object and uses the `ar` feature to update the archive file. If the
underlying filesystem does not have sub-second timestamp resolution and
the system is fast enough (or `ccache` is used), the timestamp of the
builds which should be added to the previously generated archive is the
same as the archive file itself and therefore `make` does not update the
archive.

Since OpenBLAS takes care to not run the different targets updating the
archive in parallel, the easiest solution is to declare the respective
targets `.PHONY`, forcing `make` to always update them.

fixes #1682

This was added in #1046 citing a problem with mingw, but in effect it quietly reduces thread safety on all non-Windows platforms (while -fopenmp is already disabled for Windows builds through the toplevel Makefile.system). Removing the filter fixes #1425