Have c_check probe availability of C11 atomics support and stdatomic.h

Update cross-compiling example in README to reflect change in Loongson gcc

for #2723

Handle lack of fortran compiler more gracefully in cmake

Add new linker option for POWER10

While building with DYNAMIC_ARCH on POWER9 with POWER10
aware toolchain, new LDFLAG is needed to avoid POWER10
instructions on PLT calls .

rebase

[WIP] fix compilation on AIX

Add flang build to Github Actions

Fix OpenMP builds defaulting to singlethreading with OMP_PLACES or OMP_PROC_BIND set

Add LAPACK-TESTING to the cmake build

Change minimum gcc version for POWER10

As the MMA patches for POWER10 are backported to gcc10.2, changing
the minimum gcc version needed to build OpenBLAS for POWER10.

Changing mcpu option as power10

As compiler enabled mcpu option as power10, changing it from future.

Always obey omp_get_max_threads() when build with USE_OPENMP

RFC: Use -dumpfullversion to get minor version on gcc-7 and newer

Compatibility fix for gcc < 4.7

rebase

AIX build on POWER8 32bits

Add autodetection of Intel Comet Lake H and S models

rebase

Strip UTF8 byte order marker from source files