ffx_a.h, ffx_fsr1.h, LICENSE.txt: AMD FidelityFX Super Resolution 1.0 (MIT),
unmodified, from github.com/GPUOpen-Effects/FidelityFX-FSR at
a21ffb8f6c13233ba336352bdff293894c706575 (ffx-fsr/, license.txt).
ffx_a_glsl.h and ffx_fsr1_glsl.h are generated from them by
tools/gen_glsl_header.py.
