[PATCH v3 0/5] MR289: spirv: Clamp ftou output.

[Zebediah Figura (＠zfigura)]

SPIR-V says this is undefined behaviour, but Direct3D actually specifies that it
should clamp. Most drivers do clamp, but llvmpipe does not. Hence this fixes a
couple of tests with llvmpipe.

This does of course add overhead to the ftou instruction, but I cannot imagine
that it is a common instruction to execute. This also is not the first time we
perform such checks; cf. udiv.

--
  v3: vkd3d-shader/spirv: Flush NaN to zero in ftoi.
      vkd3d-shader/spirv: Clamp ftoi upper bound to INT_MAX.
      vkd3d-shader/spirv: Clamp ftoi lower bound to INT_MIN.

https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/289