BUG: Can't use imported function if extern function defined (even if not exported)

[alinalihassan]

It gives a weird bug where it says it doesn't find the function. Example:

# math.les
def extern sin(x: float) -> float

export def sin(x: float) -> float
    return sin(x)

# main.les
import math

math.sin(1.0)

It gives an error: Function sin not in current scope.