FExpression::CheckObjectSupportsCustomHLSL

Some expressions may support passing object types to custom HLSL expressions [CheckObjectSupportsCustomHLSL()](API\Runtime\Engine\HLSLTree\FExpression\CheckObjectSupportsCustomHLSL) will return true if this is supported If supported, [GetObjectCustomHLSLParameter()](API\Runtime\Engine\HLSLTree\FExpression\GetObjectCustomHLSLParameter) will generate code to declare the parameters in the custom HLSL function, and forward the parameters [EmitValueShader()](API\Runtime\Engine\HLSLTree\FExpression\EmitValueShader) will be called to generate the actual HLSL code for the expression