Make a new object using two different object in JavaScript

I have two objects. I am trying to do like :

var obj1 = {
 abc_name: "Jack", 
 abc_age: 24
}

var obj2 = {
 xyz_name: "Mike", 
 xyz_age: 22
}

Expected Output be like :

var obj = [{
 fieldName: "Name", 
 abc_name: "Jack", 
 xyz_name: "Mike"
}, 
{
 fieldName: "Age", 
 abc_age: 24, 
 xyz_age: 22
}]

I am trying with the nested for-in loop. But not getting expected results. Any better solution or idea ? Thanks in advance