Why declare analog pins as ints?
The board definition (pins_arduino.h) has this:

static const uint8_t A0 = 14;
static const uint8_t A1 = 15;
static const uint8_t A2 = 16;
static const uint8_t A3 = 17;
static const uint8_t A4 = 18;
static const uint8_t A5 = 19;
static const uint8_t A6 = 20;
static const uint8_t A7 = 21;


Since A0 is a constant variable equal to 14, if you assign that to a variable, it just assigns 14.

In other words: 

A = 14.
B = A.
Therefore B = 14.