Duplicate declaration of functions (multiple signatures)

---

examples/functions/duplicate_add.py

def add(x, y):
    return x*y

print(add(2, 3))  # 6

def add(x):
    return x+x

print(add(2))  # 4

add(2, 3)
# TypeError: add() takes exactly 1 argument (2 given)

4
Traceback (most recent call last):
  File "examples/functions/duplicate_add.py", line 9, in <module>
    add(2, 3)
TypeError: add() takes 1 positional argument but 2 were given

The second declaration silently overrides the first declaration.