Control the number of threads on 'BLAS' (Aka 'GotoBLAS', 'ACML' and 'MKL').
If you build R directly on Windows and the BLAS file name is not
'Rblas.dll', you can give it as 'options ("RhpcBLASctl.win.Rblas.name" = "boofoo.dll")'.
openmp-related functions only work at build-time instructions.
Omp_get * now returns NA_Integer if R was not built with openmp instructions.
NOTE: if R itself is built without OpenMP instructions and BLAS thread
is used with OpenMP, this package will not work...XD