- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
Adds the `gearshifft` package, a benchmark suite for heterogeneous implementations of FFTs.
Adds clFFT, a software library containing FFT functions written in OpenCL.
see: https://github.com/clMathLibraries/clFFT