{"ast_node_type":"variable","tokens":[{"end":96,"kind":"keyword","start":0,"text":"let"}]}
                                    let (op, _): &(InlineAsmOperand, Span) = &asm.operands[idx];
                                    // so we have to retrieve it from AST
                                    if let Some(ast::InlineAsmRegOrRegClass::Reg(reg_sym)) =