Function build_upvar_field_di_nodes

fn build_upvar_field_di_nodes<'ll, 'tcx>(
    cx: &CodegenCx<'ll, 'tcx>,
    closure_or_coroutine_ty: Ty<'tcx>,
    closure_or_coroutine_di_node: &'ll DIType,
) -> SmallVec<[&'ll DIType; 16]>

Builds the DW_TAG_member debuginfo nodes for the upvars of a closure or coroutine. For a coroutine, this will handle upvars shared by all states.