LAPACKE fixes from lapack PR249

Copied from Reference-LAPACK/lapack#249, this fixes out-of-bounds memory accesses
in the nancheck calls of the LAPACKE lacgv, lassq,larfg,larfb,larfx and mtr functions

To allow compiling with gcc versions older than 4.9

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

From Reference-LAPACK issue 228, remove spurious EXTERNAL reference to unused and nonexistent function xLACGV that could cause linking problems.

The macOS ar aborts when it gets called with no input, see #1398

Inf values in the input vector will survive rescaling, causing an infinite loop. The value of 1000 is arbitrarily chosen as a large but finite value with the intention to never interfere with regular calculations.

From netlib PR#144

From netlib PR#144

From netlib PR#144

from netlib PR #144

* Fix integer overflow in DBDSQR

As noted in lapack issue 135, an integer overflow in the calculation of the iteration limit could lead to an immediate return without any iterations having been performed if the input matrix is sufficiently big.

* Fix integer overflow in SBDSQR

As noted in lapack issue 135, an integer overflow in the calculation of the iteration limit could lead to an immediate return without any iterations having been performed if the input matrix is sufficiently big.

* Fix integer overflow in threshold calculation

Related to lapack issue 135, the threshold calculation can overflow as well as the multiplication is evaluated from left to right.
Without explicit parentheses, the calculation would overflow for N >= 18919

* Fix integer overflow in threshold calculation

Related to lapack issue 135, the threshold calculation can overflow as well as the multiplication is evaluated from left to right.
Without explicit parentheses, the calculation would overflow for N >= 18919

Remove unused (and nonexistent) functions ZHETRD_SY2SB and ZHETRD_SB2ST from comment and EXTERNAL declaration

Remove unused (and nonexistent) ZHETRD_SY2SB and ZHETRD_SB2ST

ZHBTRD_HB2ST  should be ZHETRD_HB2ST

EXTERNAL declaration of subroutines missed a comma before the continuation line,
causing a strange run-together name to appear in the object when compiled with ifort.

EXTERNAL declaration of subroutines missed a comma before the continuation line,
causing a strange run-together name to appear in the object when compiled with ifort.

EXTERNAL declaration of subroutines missed a comma before the continuation line,
causing a strange run-together name to appear in the object when compiled with ifort.

EXTERNAL declaration of subroutines missed a comma before the continuation line,
causing a strange run-together name to appear in the object when compiled with ifort.

Changes made upstream in Reference LAPACK in
https://github.com/Reference-LAPACK/lapack/pull/128

Copied from lapack https://github.com/Reference-LAPACK/lapack/pull/127  by vladimir-ch (with earlier changes from echeresh's  
PR 115 "lapacke_*ormlq_work: move declarations under if" there as they touched some of the same files)

Fixed in Reference LAPACK in commit:

07e1fbd897

Missed the splitting of the actual ar call

Split obj list to allow building with mingw (argument list too long for the msys ar)

Closes #971

Trivial typo correction (ZERBLA => XERBLA) to fix #910

If OpenBLAS is built using add_subdirectory(OpenBlas) as part of another project
then the paths set by CMAKE_XXX_DIR are relative to the parent project
and not the OpenBLAS project.