[BUG] Cannot initialise container in the constructor under certain conditions

[guybrush77]

Describe the bug

Cannot initialise container in the constructor under certain conditions.

To Reproduce

Consider this code:

foo: type = {
    m: std::map<int, int>;
    operator=: (out this, bar: int) = { m = ( std::pair(1, 2), std::pair(3, 4) ); }
}

main: () = {
    f := foo(5);
}

I get this error using MSVC:

repro.cpp(7): error C2679: binary '=': no operator found which takes a right-hand operand of type 'std::pair<int,int>' (or there is no acceptable conversion)

If I remove the bar parameter then it works.

[JohelEGP]

This was supposed to have been fixed by #487.
The assignment works outside operator=.
But it looks like there's separate logic for emitting operator=.