The OSL dependency is built with target sm_50 currently, which means
that LLVM defaults to generating PTX version 4.0. However, due to an
apparent bug in LLVM 20 it still uses instructions that were only
introduced in PTX version 6.0. As a result OptiX refuses to load the
shadeops PTX with an `OPTIX_ERROR_INVALID_INPUT` error.
To fix this, raise the PTX version generated by LLVM to 6.0 for both the
shadeops module (which previously used 4.0) and also any generated code
(which previously used 5.0) to be safe. PTX version 6.0 was introduced with
CUDA 9, so it has pretty long driver backwards compatibility still.
This commit contains fixes for the OSL, to fully fix the original report
a recompiled OSL libraries would need to land for the affected platforms.
Ref #147361
Pull Request: https://projects.blender.org/blender/blender/pulls/147620