Create two 1/1 white Soldier creature tokens. Until end of turn, creatures you control get +1/+1 and gain haste. (They can attack and {T} this turn.)
The second part of Heroic Reinforcements's effect affects only creatures you control at the time it's applied, including the tokens created by the first part of its effect. Creatures you begin to control later in the turn won't get +1/+1 or gain haste.