Request: auto keyword for basic type deduction

[alex-mat]

Since ISPC has function overloading, automatic type deduction by function return type would be useful. It would be a simple way to allow for basic generic programming and could potentially simplify some codebases.

To keep things predictable, it could require writing the uniform/varying qualifier if required, for example:

uniform auto gatherIterator = GetIterator(variableOfSomeStructType);