Calls A_WeaponReady and checks if the current weapon has enough ammo. If so, jumps to its ReadyGlow state.
It's an equivalent of doing the following, in Timon's Axe ready state:
FAXE A 0 A_JumpIfInventory ("Mana1", 1, "ReadyGlow") FAXE A 1 A_WeaponReady loop
This codepointer is restricted to FWeapAxe and derived classes.