求助：

原数据格式

    var list = [{
                    spec: [{
                        keyName: "颜色",
                        valueName: "红色"
                    }, {
                        keyName: "大小",
                        valueName: "XL"
                    }]
                },
                {
                    spec: [{
                        keyName: "颜色",
                        valueName: "绿色"
                    }, {
                        keyName: "大小",
                        valueName: "XL"
                    }]
                }
            ]

期望拼凑成以下数据格式

var attrs = [
           {
             pName: '颜色',
             spec: [
               {cName:'红色'},
               {cName:'绿色'}
             ]
           },
           {
             pName: '大小',
             spec: [
               {cName:'XL'}
             ]
           }
         
         ]