Reassigning function parameters breaks function calls

[YuriGen2423]

function func(x:number) {
    x = Math.floor(x)
    return x
}

print(func(Vars.ipt))
printFlush()

gives The operator '=' is not defined for [1].
expected something like:

op floor func:smth @ipt
print func:smth
printflush message1

because before it wasn't broken

[JeanJPNM]

This will be fixed by #222.

This is a consequence of the current implementation of function inlining, which essentially replaces the parameters in the function body by the received values, generates the mlog code and then checks if it is short enough to inline. This means that for this code:

function func(x: number) {
    x = Math.floor(x)
    return x
}

print(func(1))
printFlush()

The compiler generates this internal function to see if the generated code is short enough to be inlined:

function func__0() {
    1 = Math.floor(1)
    return 1
}

And then it sees that 1 = Math.floor(1) is an invalid assignment, so it throws an error.