Okay so let's take a look at our code and what that translates to in ARM:
ldrb w1, [x0, #0x3e] // Loads the value of x0 (as a byte) (first parameter passed) + offset 0x3e (which is m_friendship in BTL_POKEPARAM) into w1
cbz w1, #0xc // Checks if this value is 0, if it isn't, it will execute...