Compiler not able to generate Bell state with non-native gates

[andrea-pasquale]

Following #1044 I was able to generate a Bell circuit using native gates.

from qibo import gates, Circuit

circuit = Circuit(2)
circuit.add(gates.GPI2(0, phi=np.pi/2))
circuit.add(gates.GPI2(1, phi=np.pi/2))
circuit.add(gates.CZ(0, 1))
circuit.add(gates.X(0))
circuit.add(gates.GPI2(1, phi=np.pi/2))
circuit.add(gates.M(0,1))

print(circuit().frequencies())

However, when I try to run Bell using generic gates

from qibo import gates, Circuit

circuit = Circuit(2)
circuit.add(gates.H(0))
circuit.add(gates.H(1))
circuit.add(gates.CZ(0, 1))
circuit.add(gates.H(1))
circuit.add(gates.M(0,1))

print(circuit().frequencies())

The results are completely wrong. We might need to debug it to understand if this issue is related to miscalibration or if there is still something to be fixed in the compiler.