I think this was there for generic support for functions actually and
that for OpenCL + TGSI the idea was to not inline everything by
default, so return values were handled there as well.
The proper way to handle is, to declare kernel inputs as real inputs,
because kernel inputs are fundamentally
With OpenCL, kernels can take arguments and return values (?). However
in practice, there is no more TGSI compute implementation, and even if
there were, it would probably have named functions and no explicit main.
This improves RA considerably for compute shaders, since temps are not
kept around
