1. Move jsInteropFunctionsLowering after callable reference lowering, so it can continue to deal with just functions and function calls. 2. Generate lowered closure class in JsInteropFunctionsLowering because
1. Move jsInteropFunctionsLowering after callable reference lowering, so it can continue to deal with just functions and function calls. 2. Generate lowered closure class in JsInteropFunctionsLowering because