Macro define_extension_runtime 

define_extension_runtime!() { /* proc-macro */ }

Generate a standard extension runtime and registration function.

The execute function must have this signature: fn<B: BackendBound + 'static>(&OpType, &[&Tensor], &mut ExtensionExecutionContext<'_, B>).

execute_reads is required. It must have this signature: fn<B: BackendBound + 'static>(&OpType, &[TensorRead<'_>], &mut ExtensionExecutionContext<'_, B>).