A perceptron is a simple type of neural network that is very fast to use when already trained. So it is a real network, I don't know what hashed perceptron is but I'd guess it would have to do something with hashing the inputs to the perceptron?
"Hashed" in this case simply means they did some extra work to deal with the perceptron's XOR problem, since a straight mapping of PC and branch history would led to an inability to distinguish XOR patterns.